Sleuthic

The Black Files · October 22, 2026 · Difficulty: Elite

Black File #133 — SolutionStanding Room Only

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The case

Gregory Doyle, critic, was found dead at Palace Theater at 7:10 AM. Seven people were at the scene. Exactly one of them was alone with Gregory in the same zone.

The evidence (11 clues)
  1. Diane was standing on stairs.
  2. Andre was standing on the floor.
  3. Franklin was standing on the floor.
  4. Elena and Franklin were in the same zone.
  5. Celia was the westernmost person at the scene.
  6. Andre was farther west than Brian.
  7. Andre was farther north than Brian.
  8. Brian was farther north than Celia.
  9. Diane was farther north than Elena.
  10. Franklin was farther west than Diane.
  11. Diane was farther west than Andre.

The answer

The killer: Andre Underwood, alone with Gregory Doyle in the Backstage.

Nothing is forced until you test Diane at C1, E1, C4 or D6: every wrong cell leaves someone with no possible cell. With Diane at E1 the rest cascades and leaves Andre alone with Gregory in the Backstage.

Step-by-step deduction

  1. Before placing anyone, each clue eliminates cells:
  2. • Diane: was on the stairs; was farther north than Elena, and Elena is no farther than row 7; was farther west than Andre, and Andre is no farther than column F; Franklin was farther west than Diane, and Franklin is at least at column B. Remaining: C1, E1, C4 and D6.
  3. • Andre: was standing on the floor; was farther west than Brian, and Brian is no farther than column G; was farther north than Brian, and Brian is no farther than row 6; Diane was farther west than Andre, and Diane is at least at column C. Remaining: D1, F1, E4, D5 and F5.
  4. • Celia: was the westernmost person of all, and since there is one person per column somebody occupies column A: that is Celia; Brian was farther north than Celia, and Brian is at least at row 2. Remaining: A3, A4, A5, A6 and A7.
  5. • Franklin: was standing on the floor; was farther west than Diane, and Diane is no farther than column E; column A belongs to Celia. Remaining: D1, C2, B5, D5 and C7.
  6. • Still wide open: Brian (12), Elena (28) and Gregory (34) possible cells; they close as the others are placed.
  7. At this point no cell is forced. Time to test a hypothesis. Try Diane, who can only be at C1, E1, C4 or D6.
  8. – Diane at C1: forces Andre at E4, Celia at A7 and Franklin at B5, and then Elena is left with no possible cell. Impossible.
  9. – Diane at E1: everything fits: it yields Andre at F5, Celia at A7, Brian at G6, Elena at B3, Franklin at C2 and Gregory at D4.
  10. – Diane at C4: forces Franklin at B5, and then Elena is left with no possible cell. Impossible.
  11. – Diane at D6: Elena is left with no possible cell. Impossible.
  12. So Andre goes to F5, Celia goes to A7, Diane goes to E1, Brian goes to G6, Franklin goes to C2, Gregory goes to D4 and Elena goes to B3.
  13. With all seven placed, the only people in the Backstage are Gregory and Andre: Andre was alone with the victim.
Solved map of Black File #133: Andre F5, Brian G6, Celia A7, Diane E1, Elena B3, Franklin C2, Gregory D4
The solved map: Andre F5, Brian G6, Celia A7, Diane E1, Elena B3, Franklin C2, Gregory D4.

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