Murder mystery sudoku — the daily cases for 23 October 2026

Every detective in the world got these same crime scenes on 2026-10-23 — each difficulty published twice, once untimed and once as time attack. Each case is procedurally generated and then proved to have exactly one logical solution before it is published, including the cases where somebody is lying. You place every suspect back on the map using only their testimony: exactly one person per row, never two in a column. Whoever is left alone with the victim did it.

Beginner — The Old Observatory

A 5×5 grid across 4 rooms: Terrace, Office, Cellar, Garden. Five statements, six squares nobody could stand on, and no assumption anywhere: elimination alone closes it.

Cracked by 12 detectives so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

The testimony

What each person said, and how much of the board it rules out.

Kaspar was in column 2. leaves 5 of 21 squares
Show it on the board
The squares this one statement leaves Kaspar: 5 of 21.
Kaspar was in the office. leaves 1 of 21 squares
Show it on the board
The squares this one statement leaves Kaspar: 1 of 21.
Marco was in the cellar. leaves 4 of 21 squares
Show it on the board
The squares this one statement leaves Marco: 4 of 21.
Selma was in row 4. leaves 5 of 21 squares
Show it on the board
The squares this one statement leaves Selma: 5 of 21.
Irene was in the garden. leaves 3 of 21 squares
Show it on the board
The squares this one statement leaves Irene: 3 of 21.

Show the squares Irene had left

The squares still open to Irene once their own statements are taken into account — 3 of 21.

What the testimony settles on its own

Nobody shares a row or a column, so each placement narrows everyone else. Before a single guess:

Marco can only be in Cellar (row 5, column 1) — down from 4 possible squares.
Selma can only be in Terrace (row 4, column 4) — down from 5 possible squares.
Tobias can only be in Terrace (row 3, column 5) — down from 21 possible squares.
Irene can only be in Garden (row 2, column 3) — down from 3 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Selma, in Terrace (row 4, column 4).

Show the solved board

The only arrangement the testimony allows. Selma is ringed in red.

Beginner · time attack — The Old Observatory

A 5×5 grid across 4 rooms: Garden, Office, Terrace, Dome. Six statements, seven squares nobody could stand on, and no assumption anywhere: elimination alone closes it.

Cracked by 3 detectives so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. A — armchair (square stays free) · B — bonsai · F — flower bush · R — round table · S — sofa (square stays free) · T — tree · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Vasco was seated on the sofa. leaves 2 of 21 squares
Show it on the board
The squares this one statement leaves Vasco: 2 of 21.
Vasco was in column 2. leaves 1 of 21 squares
Show it on the board
The squares this one statement leaves Vasco: 1 of 21.
Julia was in row 4. leaves 5 of 21 squares
Show it on the board
The squares this one statement leaves Julia: 5 of 21.
Irene was in the top row. leaves 5 of 21 squares
Show it on the board
The squares this one statement leaves Irene: 5 of 21.
Irene was in the rightmost column. leaves 1 of 21 squares
Show it on the board
The squares this one statement leaves Irene: 1 of 21.
Quentin was in the telescope dome. leaves 7 of 21 squares
Show it on the board
The squares this one statement leaves Quentin: 7 of 21.

Show the squares Julia had left

The squares still open to Julia once their own statements are taken into account — 5 of 21.

What the testimony settles on its own

Nobody shares a row or a column, so each placement narrows everyone else. Before a single guess:

Julia can only be in Terrace (row 4, column 4) — down from 5 possible squares.
Paloma can only be in Terrace (row 5, column 3) — down from 21 possible squares.
Quentin can only be in Dome (row 2, column 1) — down from 7 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Julia, in Terrace (row 4, column 4).

Show the solved board

The only arrangement the testimony allows. Julia is ringed in red.

Easy — The Old Observatory

A 6×6 grid across 5 rooms: Lounge, Dome, Garden, Library, Archive. Seven statements, eleven squares nobody could stand on, and no assumption anywhere: elimination alone closes it.

Cracked by 10 detectives so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. B — bonsai · CA — carpet (square stays free) · CH — chest · FL — floor lamp · FO — flower bush · P — potted plant · S — statue · TE — telescope · TR — tree · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Luna was in the telescope dome. leaves 4 of 28 squares
Show it on the board
The squares this one statement leaves Luna: 4 of 28.
Selma was beside the carpet. leaves 2 of 28 squares
Show it on the board
The squares this one statement leaves Selma: 2 of 28.
Hugo was in the library. leaves 4 of 28 squares
Show it on the board
The squares this one statement leaves Hugo: 4 of 28.
Julia was beside the statue. leaves 2 of 28 squares
Show it on the board
The squares this one statement leaves Julia: 2 of 28.
Julia was in column 4. leaves 1 of 28 squares
Show it on the board
The squares this one statement leaves Julia: 1 of 28.
Bianca was in column 2. leaves 3 of 28 squares
Show it on the board
The squares this one statement leaves Bianca: 3 of 28.
Bianca was in row 5. leaves 1 of 28 squares

Show the squares Selma had left

The squares still open to Selma once their own statements are taken into account — 2 of 28.

What the testimony settles on its own

Nobody shares a row or a column, so each placement narrows everyone else. Before a single guess:

Luna can only be in Dome (row 1, column 6) — down from 4 possible squares.
Selma can only be in Lounge (row 6, column 1) — down from 2 possible squares.
Hugo can only be in Library (row 4, column 5) — down from 4 possible squares.
Gilda can only be in Archive (row 2, column 3) — down from 28 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Julia, in Archive (row 3, column 4).

Show the solved board

The only arrangement the testimony allows. Julia is ringed in red.

Easy · time attack — The Old Observatory

A 6×6 grid across 4 rooms: Dome, Workshop, Garden, Archive. Seven statements, nine squares nobody could stand on, and no assumption anywhere: elimination alone closes it.

Cracked by 2 detectives so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. B — bookshelf · C — crate · D — desk · F — floor lamp · G — grandfather clock · SO — sofa (square stays free) · ST — statue · T — tree · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Leo was beside the floor lamp. leaves 2 of 29 squares
Show it on the board
The squares this one statement leaves Leo: 2 of 29.
Gilda was beside the bookshelf. leaves 2 of 29 squares
Show it on the board
The squares this one statement leaves Gilda: 2 of 29.
Tamara was in the telescope dome. leaves 5 of 29 squares
Show it on the board
The squares this one statement leaves Tamara: 5 of 29.
Tamara was beside the window. leaves 1 of 29 squares
Show it on the board
The squares this one statement leaves Tamara: 1 of 29.
Hilda was in the telescope dome. leaves 5 of 29 squares
Show it on the board
The squares this one statement leaves Hilda: 5 of 29.
Nestor was beside the tree. leaves 2 of 29 squares
Show it on the board
The squares this one statement leaves Nestor: 2 of 29.
Nestor was in row 4. leaves 1 of 29 squares

Show the squares Leo had left

The squares still open to Leo once their own statements are taken into account — 2 of 29.

What the testimony settles on its own

Nobody shares a row or a column, so each placement narrows everyone else. Before a single guess:

Leo can only be in Workshop (row 3, column 5) — down from 2 possible squares.
Sofia can only be in Archive (row 6, column 6) — down from 29 possible squares.
Gilda can only be in Archive (row 5, column 2) — down from 2 possible squares.
Hilda can only be in Dome (row 1, column 3) — down from 5 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Gilda, in Archive (row 5, column 2).

Show the solved board

The only arrangement the testimony allows. Gilda is ringed in red.

Medium · time attack — The Old Observatory

An 8×7 grid across 5 rooms: Workshop, Office, Library, Terrace, Cellar. Eleven statements, thirteen squares nobody could stand on, and one round of assume-and-test after elimination ran dry.

Cracked by one detective so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. A — armchair (square stays free) · B — bonsai · CA — carpet (square stays free) · CH — chest · CR — crate · D — desk · FL — floor lamp · FO — flower bush · P — potted plant · R — round table · T — telescope · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Margot was touching the outer wall. leaves 20 of 47 squares
Margot was in the same room as the Chauffeur.
Rufus was in the same column as a window. leaves 12 of 47 squares
Show it on the board
The squares this one statement leaves Rufus: 12 of 47.
Rufus was in the same room as Fabio.
Rufus was somewhere east of Xavier.
Fabio was in the same row as the armchair. leaves 7 of 47 squares
Show it on the board
The squares this one statement leaves Fabio: 7 of 47.
Xavier was in column 3. leaves 6 of 47 squares
Show it on the board
The squares this one statement leaves Xavier: 6 of 47.
Kurt was in the library or in the cellar. leaves 18 of 47 squares
Show it on the board
The squares this one statement leaves Kurt: 18 of 47.
Kurt was in the same row as the potted plant. leaves 2 of 47 squares
Show it on the board
The squares this one statement leaves Kurt: 2 of 47.
Greta was beside the desk. leaves 3 of 47 squares
Show it on the board
The squares this one statement leaves Greta: 3 of 47.
Nobody was in the terrace.

Show the squares Kurt had left

The squares still open to Kurt once their own statements are taken into account — 2 of 47.

The squares that had to be tested

The rest does not fall out on its own. It takes 59 eliminations of the same move: put someone on a square, follow the consequences, and watch the board contradict itself.

Had Yolanda stood in Library (row 1, column 3), Xavier would have had nowhere left to stand. So not there.
Put Margot in Library (row 1, column 4) and the testimony cannot be satisfied at all. So not there.
Had Rufus stood in Office (row 2, column 5), Kurt would have had nowhere left to stand. So not there.
Had Fabio stood in Cellar (row 6, column 4), Xavier would have had nowhere left to stand. So not there.

Show what goes wrong

Suppose Yolanda stood on the dashed square. Xavier then has nowhere left to stand: every square still open to them is shaded out.

Another 55 squares fell the same way.

The answer

That leaves one arrangement, and one person who could have done it: Greta, in Office (row 3, column 7).

Show the solved board

The only arrangement the testimony allows. Greta is ringed in red.

Medium — The Old Observatory

An 8×7 grid across 5 rooms: Workshop, Garden, Terrace, Cellar, Office. Twelve statements, thirteen squares nobody could stand on, and enough testimony that the surplus is what pins the last two down.

Cracked by 8 detectives so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. BK — bookshelf · BO — bonsai · CA — carpet (square stays free) · CH — chest · CR — crate · D — desk · F — flower bush · G — grandfather clock · R — round table · S — statue · TE — telescope · TR — tree · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Julia was somewhere east of Nadia.
Julia was in the same room as the Chef.
Julia was in the same room as Wilfred.
Julia was in the same row as the carpet. leaves 15 of 45 squares
Show it on the board
The squares this one statement leaves Julia: 15 of 45.
Nadia was in the same room as Zaida.
Wilfred was in the same row as the tree. leaves 6 of 45 squares
Show it on the board
The squares this one statement leaves Wilfred: 6 of 45.
Wilfred was somewhere west of Nadia.
Ignacio was beside the crate. leaves 2 of 45 squares
Show it on the board
The squares this one statement leaves Ignacio: 2 of 45.
Zaida was beside the bonsai. leaves 3 of 45 squares
Show it on the board
The squares this one statement leaves Zaida: 3 of 45.
Zaida was in the same row as the crate. leaves 1 of 45 squares
Show it on the board
The squares this one statement leaves Zaida: 1 of 45.
Elena was in row 6. leaves 8 of 45 squares
Show it on the board
The squares this one statement leaves Elena: 8 of 45.
Elena was in the eastern half of the scene. leaves 4 of 45 squares

Show the squares Ignacio had left

The squares still open to Ignacio once their own statements are taken into account — 2 of 45.

What the testimony settles on its own

Nobody shares a row or a column, so each placement narrows everyone else. Before a single guess:

Julia can only be in Garden (row 7, column 3) — down from 15 possible squares.
Nadia can only be in Terrace (row 3, column 2) — down from 45 possible squares.
Wilfred can only be in Garden (row 5, column 1) — down from 6 possible squares.
Ignacio can only be in Cellar (row 2, column 7) — down from 2 possible squares.
Yolanda can only be in Cellar (row 4, column 8) — down from 45 possible squares.
Elena can only be in Garden (row 6, column 5) — down from 4 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Ignacio, in Cellar (row 2, column 7).

Show the solved board

The only arrangement the testimony allows. Ignacio is ringed in red.

Hard — The Old Observatory

A 9×8 grid across 7 rooms: Terrace, Dome, Lounge, Office, Archive, Library, Garden. Eleven statements, sixteen squares nobody could stand on, almost as many rooms as suspects, so a room claim nearly names a square, and one round of assume-and-test after elimination ran dry.

The twist: the accusation also demands the motive, not just the name.

Cracked by 7 detectives so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. A — armchair (square stays free) · B — bonsai · CA — carpet (square stays free) · CH — chest · CR — crate · F — flower bush · G — grandfather clock · P — potted plant · R — round table · S — statue · T — telescope · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Hilda was somewhere south of the Journalist.
Hilda was beside the bonsai. leaves 2 of 60 squares
Show it on the board
The squares this one statement leaves Hilda: 2 of 60.
Tesa was in the same column as the statue. leaves 6 of 60 squares
Show it on the board
The squares this one statement leaves Tesa: 6 of 60.
Tesa was in the same room as Fabio.
Zeno was in the same row as a window. leaves 14 of 60 squares
Show it on the board
The squares this one statement leaves Zeno: 14 of 60.
Ines was in the same column as the armchair. leaves 7 of 60 squares
Show it on the board
The squares this one statement leaves Ines: 7 of 60.
Fabio was exactly 5 rows south of the Professor.
Ximena was exactly 4 columns east of Fabio.
Pablo was exactly 5 columns east of the Magician.
Pablo was in the same column as the chest. leaves 7 of 60 squares
Show it on the board
The squares this one statement leaves Pablo: 7 of 60.
Pablo was in the same row as the carpet. leaves 2 of 60 squares
Show it on the board
The squares this one statement leaves Pablo: 2 of 60.

Show the squares Hilda had left

The squares still open to Hilda once their own statements are taken into account — 2 of 60.

The squares that had to be tested

The rest does not fall out on its own. It takes 80 eliminations of the same move: put someone on a square, follow the consequences, and watch the board contradict itself.

Had Hilda stood in Terrace (row 2, column 5), Ximena would have had nowhere left to stand. So not there.
Put Tesa in Office (row 3, column 2) and the testimony cannot be satisfied at all. So not there.
Had Simon stood in Terrace (row 1, column 1), Zeno would have had nowhere left to stand. So not there.
Put Zeno in Terrace (row 4, column 1) and the testimony cannot be satisfied at all. So not there.

Show what goes wrong

Suppose Hilda stood on the dashed square. Ximena then has nowhere left to stand: every square still open to them is shaded out.

Another 76 squares fell the same way.

The motive

This case demands the why as well as the who: naming the killer without proving the motive counts for nothing. 7 motives are in play, and these statements narrow them.

Zeno's motive would have been inheritance.
Fabio's motive would have been obsession.
Pablo's motive would have been blackmail.
Hilda's motive would have been jealousy.
Whoever did it was not driven by ambition.
Whoever did it was not driven by buried secrets.

The answer

That leaves one arrangement, and one person who could have done it: Ximena, in Library (row 2, column 9).

The only motive left standing for Ximena is revenge.

Show the solved board

The only arrangement the testimony allows. Ximena is ringed in red.

Hard · time attack — The Old Observatory

A 9×8 grid across 7 rooms: Terrace, Archive, Cellar, Garden, Lounge, Dome, Library. Fourteen statements, seventeen squares nobody could stand on, almost as many rooms as suspects, so a room claim nearly names a square, and one round of assume-and-test after elimination ran dry.

Cracked by one detective so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. A — armchair (square stays free) · BK — bookshelf · BO — bonsai · D — desk · FL — floor lamp · FO — flower bush · G — grandfather clock · P — potted plant · R — round table · SO — sofa (square stays free) · ST — statue · T — tree · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Rosa was exactly 7 columns east of the Colonel.
Rosa was somewhere north of the Butler.
Rosa was exactly 6 columns east of the Chauffeur.
Simon was exactly 1 column west of Rosa.
Simon was in the same row as the sofa. leaves 14 of 59 squares
Show it on the board
The squares this one statement leaves Simon: 14 of 59.
Dorian was in the same row as the flower bush. leaves 6 of 59 squares
Show it on the board
The squares this one statement leaves Dorian: 6 of 59.
Dorian was somewhere north of the Chef.
Dorian was somewhere west of Lidia.
Enzo was exactly 1 column west of Frida.
Enzo was not beside the floor lamp. leaves 56 of 59 squares
Frida was in the same column as the tree. leaves 6 of 59 squares
Show it on the board
The squares this one statement leaves Frida: 6 of 59.
Lidia was somewhere south of the Chauffeur.
Lidia was all alone in a room.
Zeno was all alone in a room.

Show the squares Dorian had left

The squares still open to Dorian once their own statements are taken into account — 6 of 59.

What the testimony settles on its own

Nobody shares a row or a column, so each placement narrows everyone else. Before a single guess:

Simon can only be in Lounge (row 4, column 8) — down from 14 possible squares.
Dorian can only be in Cellar (row 7, column 2) — down from 6 possible squares.
Frida can only be in Garden (row 8, column 7) — down from 6 possible squares.

The squares that had to be tested

The rest does not fall out on its own. It takes 25 eliminations of the same move: put someone on a square, follow the consequences, and watch the board contradict itself.

Had Rosa stood in Garden (row 5, column 9), Lidia would have had nowhere left to stand. So not there.
Had Enzo stood in Library (row 6, column 6), Lidia would have had nowhere left to stand. So not there.
Put Lidia in Dome (row 2, column 4) and the testimony cannot be satisfied at all. So not there.
Put Vera in Dome (row 1, column 1) and the testimony cannot be satisfied at all. So not there.

Show what goes wrong

Suppose Rosa stood on the dashed square. Lidia then has nowhere left to stand: every square still open to them is shaded out.

Another 21 squares fell the same way.

Rosa can only be in Lounge (row 1, column 9) — down from 2 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Enzo, in Library (row 5, column 6).

Show the solved board

The only arrangement the testimony allows. Enzo is ringed in red.

Expert — The Old Observatory

A 10×9 grid across 8 rooms: Terrace, Cellar, Archive, Garden, Library, Lounge, Dome, Workshop. Thirteen statements, eighteen squares nobody could stand on, almost as many rooms as suspects, so a room claim nearly names a square, and one round of assume-and-test after elimination ran dry.

Cracked by 4 detectives so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. A — armchair (square stays free) · B — bookshelf · CA — carpet (square stays free) · CH — chest · CR — crate · D — desk · FL — floor lamp · FO — flower bush · G — grandfather clock · P — potted plant · R — round table · SO — sofa (square stays free) · ST — statue · TE — telescope · TR — tree · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Gaspar was exactly 7 rows north of the Butler.
Gaspar was exactly 1 row north of the Curator.
Vivienne was in the same column as the telescope. leaves 7 of 76 squares
Show it on the board
The squares this one statement leaves Vivienne: 7 of 76.
Vivienne was exactly 2 rows south of Dorian.
Nadia was in the same column as the tree. leaves 7 of 76 squares
Show it on the board
The squares this one statement leaves Nadia: 7 of 76.
Queralt was exactly 1 column west of Jimena.
Queralt was all alone in a room.
Cesar was exactly 6 columns west of Rosa.
Dorian was exactly 1 column east of the Heiress.
Jimena was somewhere north of Rosa.
Rosa was exactly 4 rows south of the Colonel.
Exactly 2 people were in the library.
Exactly 3 people were in the terrace.

Show the squares Vivienne had left

The squares still open to Vivienne once their own statements are taken into account — 7 of 76.

The squares that had to be tested

The rest does not fall out on its own. It takes 194 eliminations of the same move: put someone on a square, follow the consequences, and watch the board contradict itself.

Had Gaspar stood in Dome (row 1, column 1), Vivienne would have had nowhere left to stand. So not there.
Had Nadia stood in Garden (row 2, column 10), Gaspar would have had nowhere left to stand. So not there.
Put Queralt in Dome (row 1, column 2) and the testimony cannot be satisfied at all. So not there.
Had Cesar stood in Workshop (row 8, column 1), Vivienne would have had nowhere left to stand. So not there.

Show what goes wrong

Suppose Gaspar stood on the dashed square. Vivienne then has nowhere left to stand: every square still open to them is shaded out.

Another 190 squares fell the same way.

Gaspar can only be in Terrace (row 2, column 7) — down from 6 possible squares.
Vivienne can only be in Cellar (row 5, column 1) — down from 2 possible squares.
Nadia can only be in Garden (row 4, column 10) — down from 4 possible squares.
Queralt can only be in Lounge (row 7, column 4) — down from 3 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Rosa, in Library (row 6, column 8).

Show the solved board

The only arrangement the testimony allows. Rosa is ringed in red.

Expert · time attack — The Old Observatory

A 10×9 grid across 7 rooms: Lounge, Office, Dome, Terrace, Archive, Workshop, Cellar. Fifteen statements, twenty squares nobody could stand on, and one round of assume-and-test after elimination ran dry.

Cracked by one detective so far.

How this case was cracked — the full solution to this board, step by step

Every step below is the solver’s own — the same one that proved this board has exactly one answer. The counts are real: you can check them against the grid.

Lettered squares are objects. Most take the square out of play — which is why the counts above are of free squares, not of all of them — but the ones marked below do not: their square is still in play. A — armchair (square stays free) · BK — bookshelf · BO — bonsai · CA — carpet (square stays free) · CH — chest · CL — clock · CR — crate · D — desk · FL — floor lamp · FO — flower bush · P — potted plant · R — round table · S — statue · T — telescope · W — window (square stays free)

The testimony

What each person said, and how much of the board it rules out.

Quentin was in the same column as the flower bush. leaves 7 of 73 squares
Show it on the board
The squares this one statement leaves Quentin: 7 of 73.
Ada and Vivienne were alone together in one room.
Ada was in the same column as the bonsai. leaves 7 of 73 squares
Show it on the board
The squares this one statement leaves Ada: 7 of 73.
Kaspar was in the same column as the desk. leaves 7 of 73 squares
Show it on the board
The squares this one statement leaves Kaspar: 7 of 73.
Vivienne was somewhere east of the Heiress.
Celeste was somewhere north of the Magician.
Zeno was in the same column as the bookshelf. leaves 8 of 73 squares
Show it on the board
The squares this one statement leaves Zeno: 8 of 73.
Zeno was somewhere north of the Heiress.
Wilfred was in the same row as the window. leaves 17 of 73 squares
Show it on the board
The squares this one statement leaves Wilfred: 17 of 73.
Wilfred was all alone in a room.
Dante was somewhere south of Vivienne.
Dante was somewhere west of Kaspar.
Dante was exactly 1 row south of Celeste.
Exactly 3 people were in the telescope dome.
Exactly 2 people were in the workshop.

Show the squares Quentin had left

The squares still open to Quentin once their own statements are taken into account — 7 of 73.

The squares that had to be tested

The rest does not fall out on its own. It takes 102 eliminations of the same move: put someone on a square, follow the consequences, and watch the board contradict itself.

Had Sofia stood in Office (row 9, column 4), Zeno would have had nowhere left to stand. So not there.
Had Quentin stood in Workshop (row 3, column 10), Celeste would have had nowhere left to stand. So not there.
Had Ada stood in Archive (row 1, column 7), Quentin would have had nowhere left to stand. So not there.
Had Kaspar stood in Archive (row 1, column 5), Vivienne would have had nowhere left to stand. So not there.

Show what goes wrong

Suppose Sofia stood on the dashed square. Zeno then has nowhere left to stand: every square still open to them is shaded out.

Another 98 squares fell the same way.

Sofia can only be in Workshop (row 9, column 8) — down from 5 possible squares.
Quentin can only be in Workshop (row 6, column 10) — down from 2 possible squares.
Ada can only be in Archive (row 2, column 7) — down from 2 possible squares.
Kaspar can only be in Office (row 8, column 5) — down from 3 possible squares.
Vivienne can only be in Archive (row 1, column 9) — down from 2 possible squares.
Celeste can only be in Dome (row 4, column 6) — down from 2 possible squares.

The answer

That leaves one arrangement, and one person who could have done it: Quentin, in Workshop (row 6, column 10).

Show the solved board

The only arrangement the testimony allows. Quentin is ringed in red.

How to read a case above

The grid size is the size of the crime scene, so a 10×9 expert case is a far larger search than a 5×5 beginner one — but the difficulty is really carried by the clues, not the square count. A beginner case tells you almost directly where somebody stood. An expert case tells you where somebody was not, three times, and expects you to do the rest — and on half of them one of those statements is a lie told to protect the killer. If a case lists a motive, naming the right person is not enough on its own; you have to prove why.

How to play · Solving cases with a liar · Techniques

The day in review

Five Empty Chairs — Whatever was hidden at The Old Observatory is hidden no longer; 1 detective found it.

All ten investigations on the twenty-third of October unfolded at The Old Observatory, where none of the suspects dared tell an outright lie, though the standard hard case demanded detectives establish motive to crack its 9x8 grid. Most boards remained straightforward spatial puzzles, scaling up from modest four-room perimeters to expansive 10x9 layouts containing seven or eight rooms.

Standard play drew modest attention throughout the day. Twelve investigators sorted through the 5x5 beginner case, ten solved the 6x6 easy, eight unraveled the 8x7 medium, seven pinned down the motive on the hard board, and four successfully navigated the eight rooms of the expert challenge. Over in the quiet halls of time attack, small handfuls took up the challenge against the clock, yielding three beginner solutions, two on easy, and lone clearances on medium, hard, and expert.

A familiar name led almost every docket. Chentian claimed the quickest marks in nine of the ten investigations, charting times of 0m 11s on standard beginner, 0m 11s on standard easy, 0m 19s on standard medium, and 1m 39s on standard hard. The same investigator swept the time attacks, clocking 0m 10s on beginner, 0m 23s on easy, 2m 09s on medium, 2m 33s on hard, and 2m 21s on expert. Only the standard expert board broke the pattern, where Nicole secured top honors in 8m 36s.

Fastest detectives of the day

Beginner: chentian — 0m 11s · Easy: chentian — 0m 11s · Medium: chentian — 0m 19s · Hard: chentian — 1m 39s · Expert: Nicole — 8m 36s · Beginner · time attack: chentian — 0m 10s · Easy · time attack: chentian — 0m 23s · Medium · time attack: chentian — 2m 09s · Hard · time attack: chentian — 2m 33s · Expert · time attack: chentian — 2m 21s