The wine cellar has thick stone walls, no window and a heavy door. Nothing outside can be seen or heard there.
The front hall has a glass panel in the front door that shows the street.
The study, on the ground floor at the back, has a window onto the garden and a side window that shows the corner streetlamp.
The second-floor front room has tall windows over the street and the lamp.
The third-floor rear room has a window over the garden and the back gate.
The gate can be heard in the study and the third-floor rear room, but nowhere else.
The night. It began to snow at exactly two o’clock and was deep by morning. Nobody outside spoke to anyone inside, and nobody inside has compared notes. Everyone except the thief tells the exact truth. Wet footprints in the front hall show the thief came in from outside after the snow began.
Harold, the butler: “I bolted the front door at eleven and went down to the wine cellar to count bottles. I stayed there until six. When I came up, the snow in the street was deep. It started around two o’clock, I’d say.”
Mabel, the cook: “I went up to the third-floor rear room at ten and never left it. I heard the back gate bang around one. I woke at two and saw the first flakes cross the garden.”
Dr. Finch, the lodger: “I stayed in my second-floor front room all night. The streetlamp was dark all night, and by six the sidewalk was buried.”
Miss Crane, the secretary: “I slept on the study sofa. The corner lamp was out when I looked, and the back gate banged around one.”
Who took the pearls?
💡 Hint
For each statement, ask whether the room that person claims to be in could show or sound that detail at that hour. One detail depends on a specific moment.
Reveal answer
Harold, the butler. He says it began to snow around two, but claims to have been shut in the windowless wine cellar from eleven until six.
Step-by-step solution
- Mabel was in the third-floor rear room, which sees the garden and hears the gate. The gate at one and the first flakes at two are both things she could have seen or heard.
- Dr. Finch was in the second-floor front room, which sees the street and the lamp. The dark lamp and the buried sidewalk at six are both visible from there.
- Miss Crane was in the study. The gate can be heard there, and the side window shows the corner lamp, so both her details check out.
- Harold was in the wine cellar until six, a room that shows and sounds nothing from outside. At six he came up to the hall and could see deep snow, which is honest knowledge.
- The hour of two o’clock is different. From a windowless cellar nobody can know when the snow began, while Mabel, Dr. Finch and Miss Crane all had windows. Harold’s account cannot be true, and it is the only one that fails. Harold is the thief.
Why it fools people
The case is built on the idea that an honest-looking list of details signals innocence. Harold’s account is mostly plausible, yet he adds one detail that only someone with a view of the sky at two in the morning could know. The slip hides in a casual remark about the weather. To catch it, match every detail to a place and an hour, not to a feeling about the speaker.
Did you get it?
About This Puzzle
A tall brownstone on Marlborough Street, in Boston’s Back Bay, is home to Mrs. Lathrop, a widow, and four people who look after her. On a February night, her pearl necklace was taken from the jewel case on her dressing table. In the morning the inspector interviewed all four, one at a time. He told each only two things: the pearls were gone, and the empty case was found open. There is no confession and no fingerprint here, only one sentence that the speaker could not honestly have said.
How to Think About It
Read the layout like a map of what each room can see and hear. Then take each statement and ask one question: could this person, in the place they say they were, at the hour they mention, have known this detail? Do not ask whether they sound honest. Note the hour attached to each detail. Some details are visible all morning, others at only one moment. Remember the rule: everyone except the thief tells the truth, so you want the only statement the layout cannot support.
Common Traps
Miss Crane sat in a back room yet describes the street lamp, and the study’s side window explains it. The butler’s deep snow was seen honestly when he came upstairs. The real test is whether a detail fits where the person says they were, not how many details they offer.
Where This Puzzle Comes From
A classic device of detective fiction is the fact the culprit could not have known, a slip of the tongue that proves presence at a scene. It fits naturally with the “fair play” rule of Golden Age mysteries, which requires that the clue appear in plain sight for the reader. This case is an original construction in that tradition, and it uses a layout of sightlines to make the slip a checkable deduction.
Try This Variation
Three staff stay in a harbor house during a fireworks show at nine. Gil is in the windowless boiler room and says he saw the fireworks bright at nine. Tess is on the roof and says she saw them and saw the rain stop. Ray is on the front steps and says the rain stopped. Everyone but the thief tells the truth. Who is the thief?
Show the answer to the variation
Gil. The roof and the front steps show the harbor, so Tess’s and Ray’s details are possible. The windowless boiler room shows nothing outside, so Gil could not have seen the fireworks. His statement is the only one the layout cannot support.