The Black Files · October 28, 2026 · Difficulty: Master Detective
Black File #139 — SolutionThe Missing Key
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The case
Gordon Brennan, publisher, was found dead at The Gazette Newsroom at 9:20 PM. Seven people were at the scene. Exactly one of them was alone with Gordon in the same zone.
The evidence (9 clues)
- Carl was standing on stairs.
- Dennis was standing on the floor.
- Byron and Dennis were in the same zone.
- Byron was the easternmost person at the scene.
- Frank was the westernmost person at the scene.
- Anthony and Ernest were in the same zone.
- Ernest was farther north than Anthony.
- Byron was farther north than Frank.
- Ernest was farther west than Anthony.
The answer
The killer: Carl Winters, alone with Gordon Brennan in the Print Shop.
Nothing is forced until you test Frank at A5 or A7: every wrong cell leaves someone with no possible cell. With Frank at A7 the rest cascades and leaves Carl alone with Gordon in the Print Shop.
Step-by-step deduction
- Before placing anyone, each clue eliminates cells:
- • Dennis: was standing on the floor; column G belongs to Byron; column A belongs to Frank; was in the same zone as Byron, and Byron can only be in the Editor's Office. Remaining: F4 and E5.
- • Frank: was the westernmost person of all, and since there is one person per column somebody occupies column A: that is Frank; Byron was farther north than Frank, and Byron is at least at row 4. Remaining: A5 and A7.
- • Byron: was the easternmost person of all, and since there is one person per column somebody occupies column G: that is Byron; was farther north than Frank, and Frank is no farther than row 7; was in the same zone as Dennis, and Dennis can only be in the Bullpen, the Editor's Office or the Archive. Remaining: G4, G5 and G6.
- • Carl: was on the stairs; column G belongs to Byron. Remaining: D2, F3, D4, C5, C6, F6 and B7.
- • Still wide open: Anthony (20), Ernest (20) and Gordon (22) possible cells; they close as the others are placed.
- At this point no cell is forced. Time to test a hypothesis. Try Frank, who can only be at A5 or A7.
- – Frank at A5: Byron is left with no possible cell. Impossible.
- – Frank at A7: everything fits.
- So Frank goes to A7.
- Again, nothing is forced. Try Anthony, who can only be at C2, D2, F2, C3, D3, E3, F3, C4, D4, F4, C5, D5, E5, C6, E6 or F6.
- – Anthony at C2: forces Ernest at B1 and Gordon at B6, and then Gordon is left with no possible cell. Impossible.
- – Anthony at D2: Ernest is left with no possible cell. Impossible.
- – Anthony at F2: forces Dennis at E5 and Ernest at D1, and then Gordon is left with no possible cell. Impossible.
- – Anthony at C3: forces Carl at D2, and then Gordon is left with no possible cell. Impossible.
- – Anthony at D3: row 2 would be left empty. Impossible.
- – Anthony at E3: Ernest is left with no possible cell. Impossible.
- – Anthony at F3: Ernest is left with no possible cell. Impossible.
- – Anthony at C4: everything fits: it yields Byron at G6, Dennis at E5, Carl at D2, Ernest at B3 and Gordon at F1.
- – Anthony at D4: Anthony is left with no possible cell. Impossible.
- – Anthony at F4: Anthony is left with no possible cell. Impossible.
- – Anthony at C5: Anthony is left with no possible cell. Impossible.
- – Anthony at D5: Ernest is left with no possible cell. Impossible.
- – Anthony at E5: Anthony is left with no possible cell. Impossible.
- – Anthony at C6: Anthony is left with no possible cell. Impossible.
- – Anthony at E6: forces Byron at G5, Dennis at F4 and Ernest at D5, and then Ernest is left with no possible cell. Impossible.
- – Anthony at F6: forces Byron at G4, Dennis at E5 and Ernest at D4, and then Ernest is left with no possible cell. Impossible.
- So Anthony goes to C4, Byron goes to G6, Dennis goes to E5, Carl goes to D2, Ernest goes to B3 and Gordon goes to F1.
- With all seven placed, the only people in the Print Shop are Gordon and Carl: Carl was alone with the victim.
