Oct 4, 2026 Full Proof Walkthrough

Start: Jasper (E2) begins the case proven innocent.

None of the surgeons in Column B is innocent.— Jasper, orderly (E2)

1. Step 1: Lena (B3, surgeon) is a criminal. This follows from Jasper’s statement and the verdicts already proven.

2. Step 2: Celia (C1, private patient) is a criminal. This follows from Lena’s statement and the verdicts already proven.

   Celia and I are either both criminals or both innocent.— Lena, surgeon (B3)

3. Step 3: Bruno (B1, security guard) is innocent. This follows from Celia’s statement and the verdicts already proven.

   The person between me and Ada is innocent.— Celia, private patient (C1)

4. Step 4: Ada (A1, surgeon) is innocent. This follows from Bruno’s statement and the verdicts already proven.

   The person to my left is innocent.— Bruno, security guard (B1)

5. Step 5: Frank (A2, security guard) is innocent. This follows from Ada’s statement and the verdicts already proven.

   The only security guard in my column is innocent.— Ada, surgeon (A1)

6. Step 6: Gus (B2, cook) is a criminal. This follows from Frank’s statement and the verdicts already proven.

   Mabel and I have no innocent neighbors in common.— Frank, security guard (A2)

7. Step 7: Hana (C2, cook) is innocent. This follows from Gus’s statement and the verdicts already proven.

   The person between me and Ivan is innocent.— Gus, cook (B2)

8. Step 8: Quinn (B4, surgeon) is a criminal. This follows from Jasper’s statement and the verdicts already proven.

9. Step 9: Mabel (C3, cook) is innocent. This needs 2 statements together — Hana’s and Quinn’s. Assume the opposite verdict and at least one of them breaks.

   Exactly four of my eight neighbors are criminals.— Hana, cook (C2)

   If Mabel is a criminal, then so is Ivan.— Quinn, surgeon (B4)

10. Step 10: Dexter (D1, private patient) is innocent. This needs 2 statements together — Hana’s and Mabel’s. Assume the opposite verdict and at least one of them breaks.

    Exactly six of my eight neighbors are criminals.— Mabel, cook (C3)

11. Step 11: Ruby (C4, security guard) is a criminal. This needs 2 statements together — Hana’s and Mabel’s. Assume the opposite verdict and at least one of them breaks.

12. Step 12: Suki (D4, administrator) is a criminal. This needs 2 statements together — Hana’s and Mabel’s. Assume the opposite verdict and at least one of them breaks.

13. Step 13: Xander (D5, visitor) is innocent. This needs 2 statements together — Hana’s and Dexter’s. Assume the opposite verdict and at least one of them breaks.

    There are exactly two innocents below me.— Dexter, private patient (D1)

14. Step 14: Theo (E4, surgeon) is a criminal. This needs 2 statements together — Hana’s and Xander’s. Assume the opposite verdict and at least one of them breaks.

    Exactly two of Otto's five neighbors are innocent.— Xander, visitor (D5)

15. Step 15: Yvette (E5, private patient) is a criminal. This needs 3 statements together — Hana’s, Suki’s and Theo’s. Assume the opposite verdict and at least one of them breaks.

    Exactly four of my eight neighbors are criminals.— Suki, administrator (D4)

    An even number of the orderlies are innocent.— Theo, surgeon (E4)

16. Step 16: Wren (C5, orderly) is innocent. This needs 3 statements together — Hana’s, Suki’s and Yvette’s. Assume the opposite verdict and at least one of them breaks.

    Row 3 has more criminals than Row 2.— Yvette, private patient (E5)

17. Step 17: Ursula (A5, administrator) is innocent. This follows from Wren’s statement and the verdicts already proven.

    Vera and Pia have exactly one criminal neighbor in common.— Wren, orderly (C5)

18. Step 18: Emil (E1, administrator) is innocent. This needs 2 statements together — Suki’s and Ursula’s. Assume the opposite verdict and at least one of them breaks.

    Exactly two of Ivan's eight neighbors are criminals.— Ursula, administrator (A5)

19. Step 19: Pia (A4, visitor) is innocent. This follows from Emil’s statement and the verdicts already proven.

    Exactly three of Kurt's five neighbors are criminals.— Emil, administrator (E1)

20. Step 20: Otto (E3, orderly) is innocent. This follows from Pia’s statement and the verdicts already proven.

    Nora and Suki have exactly two innocent neighbors in common.— Pia, visitor (A4)

21. Step 21: Ivan (D2, orderly) is innocent. This follows from Theo’s statement and the verdicts already proven.

22. Step 22: Kurt (A3, visitor) is innocent. This follows from Otto’s statement and the verdicts already proven.

    Exactly thirteen of the sixteen people on the edges are innocent.— Otto, orderly (E3)

23. Step 23: Nora (D3, security guard) is a criminal. This follows from Hana’s statement and the verdicts already proven.

24. Step 24: Vera (B5, visitor) is innocent. This follows from Ruby’s statement and the verdicts already proven.

    Exactly four of my eight neighbors are criminals.— Ruby, security guard (C4)

The final lineup

What happened

The emerald never went into theatre. Yvette, short of money and long on pride, planned its 'loss' with her grand-niece Celia, whose tearful bedside video half the country watched. Lena, Quinn and Theo wrote an operation note so meticulous that nobody thought to ask about a missing jewel; Nora and Ruby, on security that night, logged a camera fault on the theatre corridor; and Suki, the administrator, pushed the claim through in one afternoon. The stone left the building baked into one of Gus's game pies, addressed to a dealer in Amsterdam who already had a buyer.