Sleuthic

The Black Files · October 8, 2026 · Difficulty: Detective

Black File #119 — SolutionDelivery Window

Missed the case? Play Black File #119 →

The case

Frank Delgado, auditor, was found dead at Riverside Warehouse at 6:05 AM. Seven people were at the scene. Exactly one of them was alone with Frank in the same zone.

The evidence (9 clues)
  1. Bonnie was standing on the stairs.
  2. Elena was standing on the floor.
  3. Bonnie was the northernmost person at the scene.
  4. Denise was the southernmost person at the scene.
  5. Calvin was the easternmost person at the scene.
  6. Angela and Denise were in the same zone.
  7. Denise was farther west than Bonnie.
  8. Elena was farther west than Gwen.
  9. Angela was farther north than Calvin.

The answer

The killer: Elena Trask, alone with Frank Delgado in the Cold Storage.

Fixing rows and columns from the extreme-position clues cascades through the board and leaves Elena alone with Frank in the Cold Storage.

Step-by-step deduction

  1. Before placing anyone, each clue eliminates cells:
  2. • Angela: was in the same zone as Denise, and Denise can only be in the Main Aisle; was farther north than Calvin, and Calvin is no farther than row 6; column D already belongs to Bonnie; column C already belongs to Denise. Only E5 is left.
  3. • Bonnie: was on the stairs; was the northernmost person of all, and since there is one person per row somebody occupies row 1: that is Bonnie; column G belongs to Calvin. Only D1 is left.
  4. • Calvin: was the easternmost person of all, and since there is one person per column somebody occupies column G: that is Calvin; Angela was farther north than Calvin, and Angela is at least at row 4; row 7 belongs to Denise; row 5 belongs to Angela. Only G6 is left.
  5. • Denise: was the southernmost person of all, and since there is one person per row somebody occupies row 7: that is Denise; was farther west than Bonnie, and Bonnie is no farther than column D. Only C7 is left.
  6. • Elena: was standing on the floor; was farther west than Gwen, and Gwen is no farther than column G; row 7 belongs to Denise; column D already belongs to Bonnie; column C already belongs to Denise; row 5 belongs to Angela; row 6 belongs to Calvin; nobody else can occupy row 3, so it must be Elena. Only B3 is left.
  7. • Frank: Frank cannot be in the Main Aisle: the crime zone holds exactly two people and Angela and Denise are already there, and with Frank that would be more than two; row 1 belongs to Bonnie; column G belongs to Calvin; column D already belongs to Bonnie; column C already belongs to Denise; row 5 belongs to Angela; column E belongs to Angela; row 6 belongs to Calvin; column B belongs to Elena; column F belongs to Gwen. Only A4 is left.
  8. • Gwen: Elena was farther west than Gwen, and Elena is at least at column A; row 1 belongs to Bonnie; column G belongs to Calvin; row 7 belongs to Denise; column D already belongs to Bonnie; column C already belongs to Denise; row 5 belongs to Angela; column E belongs to Angela; row 6 belongs to Calvin; column B belongs to Elena; nobody else can occupy row 2, so it must be Gwen. Only F2 is left.
  9. That already places Bonnie at D1, Denise at C7, Angela at E5, Calvin at G6, Elena at B3, Frank at A4 and Gwen at F2.
  10. With all seven placed, the only people in the Cold Storage are Frank and Elena: Elena was alone with the victim.
Solved map of Black File #119: Angela E5, Bonnie D1, Calvin G6, Denise C7, Elena B3, Frank A4, Gwen F2
The solved map: Angela E5, Bonnie D1, Calvin G6, Denise C7, Elena B3, Frank A4, Gwen F2.

Play today's case →