The Black Files · October 31, 2026 · Difficulty: Cadet
Black File #142 — SolutionStress Test
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The case
Claire Pruitt, informant, was found dead at Ninth Precinct at 12:50 AM. Seven people were at the scene. Exactly one of them was alone with Claire in the same zone.
The evidence (11 clues)
- Gina was sitting in a chair.
- Faye was standing on stairs.
- Edgar was standing on the floor.
- Gina was in the Front Desk.
- Bonnie was in the Interview Room.
- Anthony was sitting in a chair.
- Faye was the westernmost person at the scene.
- Anthony and Edgar were in the same zone.
- Bonnie and Denise were in the same zone.
- Bonnie was the northernmost person at the scene.
- Edgar was the southernmost person at the scene.
The answer
The killer: Faye Kim, alone with Claire Pruitt in the Squad Room.
Fixing rows and columns from the extreme-position clues cascades through the board and leaves Faye alone with Claire in the Squad Room.
Step-by-step deduction
- Before placing anyone, each clue eliminates cells:
- • Anthony: was sitting in a chair; row 7 belongs to Edgar; column A belongs to Faye; was in the same zone as Edgar, and Edgar can only be in the Evidence Locker; row 5 belongs to Gina. Only F6 is left.
- • Bonnie: was in the Interview Room; was the northernmost person of all, and since there is one person per row somebody occupies row 1: that is Bonnie; column E belongs to Gina; nobody else can occupy column G, so it must be Bonnie. Only G1 is left.
- • Claire: Claire cannot be in the Interview Room: the crime zone holds exactly two people and Bonnie and Denise are already there, and with Claire that would be more than two; row 1 belongs to Bonnie; row 7 belongs to Edgar; row 2 belongs to Faye; column A belongs to Faye; Claire cannot be in the Evidence Locker: the crime zone holds exactly two people and Anthony and Edgar are already there, and with Claire that would be more than two; row 3 belongs to Denise; row 5 belongs to Gina; column E belongs to Gina; nobody else can occupy column C, so it must be Claire. Only C4 is left.
- • Denise: was in the same zone as Bonnie, and Bonnie can only be in the Interview Room; row 1 belongs to Bonnie; row 2 belongs to Faye; column E belongs to Gina; column F already belongs to Anthony. Only D3 is left.
- • Edgar: was standing on the floor; was in the same zone as Anthony, and Anthony can only be in the Front Desk, the Squad Room or the Evidence Locker; was the southernmost person of all, and since there is one person per row somebody occupies row 7: that is Edgar; column D belongs to Denise. Only B7 is left.
- • Faye: was on the stairs; was the westernmost person of all, and since there is one person per column somebody occupies column A: that is Faye; row 7 belongs to Edgar. Only A2 is left.
- • Gina: was sitting in a chair; was in the Front Desk; row 3 belongs to Denise. Only E5 is left.
- That already places Faye at A2, Anthony at F6, Bonnie at G1, Claire at C4, Gina at E5, Denise at D3 and Edgar at B7.
- With all seven placed, the only people in the Squad Room are Claire and Faye: Faye was alone with the victim.
