The Black Files · September 29, 2026 · Difficulty: Cadet
Black File #102 — SolutionThe Loading Dock
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The case
Beth Delgado, dispatcher, was found dead at Riverside Warehouse at 9:20 PM. Seven people were at the scene. Exactly one of them was alone with Beth in the same zone.
The evidence (10 clues)
- Alvin was sitting on the sofa.
- Beth was standing on the floor.
- Felicia was in the Office Cage.
- Dennis was sitting on the sofa.
- Elena was sitting on the sofa.
- Felicia was sitting on the sofa.
- Alvin was in the Cold Storage.
- Gail was in the Main Aisle.
- Curtis was in the Loading Dock.
- Elena was the northernmost person at the scene.
The answer
The killer: Alvin Whitaker, alone with Beth Delgado in the Cold Storage.
Fixing rows and columns from the extreme-position clues cascades through the board and leaves Alvin alone with Beth in the Cold Storage.
Step-by-step deduction
- Before placing anyone, each clue eliminates cells:
- • Alvin: was sitting on the sofa; was in the Cold Storage. Only B3 is left.
- • Beth: was standing on the floor; Beth cannot be in the Office Cage: the crime zone holds exactly two people and Elena and Felicia are already there, and with Beth that would be more than two; row 3 already belongs to Alvin; column B already belongs to Alvin; row 5 belongs to Felicia; nobody else can occupy column A, so it must be Beth. Only A7 is left.
- • Curtis: was in the Loading Dock; row 3 already belongs to Alvin; column B already belongs to Alvin; row 5 belongs to Felicia; nobody else can occupy row 2, so it must be Curtis. Only C2 is left.
- • Dennis: was sitting on the sofa; row 3 already belongs to Alvin; row 1 belongs to Elena; row 5 belongs to Felicia; column G belongs to Felicia; nobody else can occupy column F, so it must be Dennis. Only F4 is left.
- • Elena: 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 Elena; column G belongs to Felicia. Only D1 is left.
- • Felicia: was in the Office Cage; was sitting on the sofa; row 1 belongs to Elena. Only G5 is left.
- • Gail: was in the Main Aisle; row 5 belongs to Felicia; column G belongs to Felicia; nobody else can occupy column E, so it must be Gail; row 7 already belongs to Beth. Only E6 is left.
- That already places Alvin at B3, Beth at A7, Curtis at C2, Dennis at F4, Elena at D1, Felicia at G5 and Gail at E6.
- With all seven placed, the only people in the Cold Storage are Beth and Alvin: Alvin was alone with the victim.
