The Black Files · October 15, 2026 · Difficulty: Senior Detective
Black File #126 — SolutionThe Understudy
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The case
David Hayes, stage manager, was found dead at Palace Theater at 3:35 PM. Seven people were at the scene. Exactly one of them was alone with David in the same zone.
The evidence (10 clues)
- Benjamin was sitting in a chair.
- Anthony was sitting on a sofa.
- Gwen was standing on the floor.
- Fiona was in the Stage.
- Esther was sitting on a sofa.
- There were exactly 2 people in the Box Office.
- Connie and Gwen were in the same zone.
- Benjamin was the westernmost person at the scene.
- Esther was the northernmost person at the scene.
- Connie was the southernmost person at the scene.
The answer
The killer: Benjamin Whitaker, alone with David Hayes in the Box Office.
Nothing is forced until you test Anthony at B2, F2, C4 or F4: every wrong cell leaves someone with no possible cell. With Anthony at F2 the rest cascades and leaves Benjamin alone with David in the Box Office.
Step-by-step deduction
- Before placing anyone, each clue eliminates cells:
- • Benjamin: was sitting in a chair; was the westernmost person of all, and since there is one person per column somebody occupies column A: that is Benjamin. Only A6 is left.
- • Esther: was sitting on the sofa; was the northernmost person of all, and since there is one person per row somebody occupies row 1: that is Esther. Only G1 is left.
- • Gwen: was standing on the floor; row 6 already belongs to Benjamin; column A already belongs to Benjamin; row 1 already belongs to Esther; column G already belongs to Esther; row 7 belongs to Connie; was in the same zone as Connie, and Connie can only be in the Dressing Room. Only E5 is left.
- • Anthony: was sitting on the sofa; row 6 already belongs to Benjamin; column A already belongs to Benjamin; row 1 already belongs to Esther; row 7 belongs to Connie. Remaining: B2, F2, C4 and F4.
- • Connie: was the southernmost person of all, and since there is one person per row somebody occupies row 7: that is Connie; column G already belongs to Esther. Remaining: B7, C7, D7 and F7.
- • Fiona: was in the Stage; column G already belongs to Esther; column E already belongs to Gwen. Remaining: F2, C3, D4 and F4.
- • Still wide open: David (9) possible cells; they close as the others are placed.
- That already places Benjamin at A6, Esther at G1 and Gwen at E5.
- At this point no cell is forced. Time to test a hypothesis. Try Anthony, who can only be at B2, F2, C4 or F4.
- – Anthony at B2: forces David at C4, and then Fiona is left with no possible cell. Impossible.
- – Anthony at F2: everything fits: it yields Connie at D7, David at B4 and Fiona at C3.
- – Anthony at C4: Fiona is left with no possible cell. Impossible.
- – Anthony at F4: only Benjamin could be in the Box Office, but there were exactly 2 people in the Box Office. Impossible.
- So Anthony goes to F2, Connie goes to D7, David goes to B4 and Fiona goes to C3.
- With all seven placed, the only people in the Box Office are David and Benjamin: Benjamin was alone with the victim.
