Sleuthic

The Black Files · October 23, 2026 · Difficulty: Elite

Black File #134 — SolutionLights Out

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The case

Gregory Patel, visiting sister, was found dead at Ellery Court Apartments at 11:15 PM. Seven people were at the scene. Exactly one of them was alone with Gregory in the same zone.

The evidence (11 clues)
  1. Aaron was sitting in a chair.
  2. Edgar was the southernmost person at the scene.
  3. There were exactly 2 people in the Laundry Room.
  4. Benjamin was farther north than Denise.
  5. Edgar was farther west than Denise.
  6. Cynthia was farther west than Felix.
  7. Benjamin was farther west than Cynthia.
  8. Denise was farther north than Aaron.
  9. Cynthia was farther west than Edgar.
  10. Benjamin was farther north than Cynthia.
  11. Aaron was farther north than Felix.

The answer

The killer: Aaron Nakamura, alone with Gregory Patel in the Apartment 3B.

Nothing is forced until you test Edgar at C7, D7 or F7: every wrong cell leaves someone with no possible cell. With Edgar at F7 the rest cascades and leaves Aaron alone with Gregory in Apartment 3B.

Step-by-step deduction

  1. Before placing anyone, each clue eliminates cells:
  2. • Edgar: was the southernmost person of all, and since there is one person per row somebody occupies row 7: that is Edgar; was farther west than Denise, and Denise is no farther than column G; Cynthia was farther west than Edgar, and Cynthia is at least at column B. Remaining: C7, D7 and F7.
  3. • Aaron: was sitting in a chair; Denise was farther north than Aaron, and Denise is at least at row 2; was farther north than Felix, and Felix is no farther than row 6. Remaining: A3, B4, F4 and C5.
  4. • Still wide open: Benjamin (9), Denise (9), Felix (12), Cynthia (17) and Gregory (34) possible cells; they close as the others are placed.
  5. At this point no cell is forced. Time to test a hypothesis. Try Edgar, who can only be at C7, D7 or F7.
  6. – Edgar at C7: only Felix could be in the Laundry Room, but there were exactly 2 people in the Laundry Room. Impossible.
  7. – Edgar at D7: then Aaron has no way out in any of the 4 cells (most often: forces Benjamin at B1 and Gregory at E1 and Gregory is left with no possible cell). Impossible.
  8. – Edgar at F7: everything fits.
  9. So Edgar goes to F7.
  10. Again, nothing is forced. Try Aaron, who can only be at A3 or B4.
  11. – Aaron at A3: Benjamin is left with no possible cell. Impossible.
  12. – Aaron at B4: everything fits: it yields Felix at E5, Gregory at A6, Benjamin at C1, Cynthia at D3 and Denise at G2.
  13. So Aaron goes to B4, Felix goes to E5, Gregory goes to A6, Benjamin goes to C1, Cynthia goes to D3 and Denise goes to G2.
  14. With all seven placed, the only people in Apartment 3B are Gregory and Aaron: Aaron was alone with the victim.
Solved map of Black File #134: Aaron B4, Benjamin C1, Cynthia D3, Denise G2, Edgar F7, Felix E5, Gregory A6
The solved map: Aaron B4, Benjamin C1, Cynthia D3, Denise G2, Edgar F7, Felix E5, Gregory A6.

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