The French girl had sunk sobbing into a chair. Poirot was looking round the room, the main features of which I have made clear by a sketch.

“Where does that door lead?” he inquired, nodding his head towards the one by the window.

“Into the next apartment, I believe,” said the inspector. “It’s bolted, anyway, on this side.”

Poirot walked across to it, tried it, then drew back the bolt and tried it again.

“And on the other side as well,” he remarked. “Well, that seems to rule out that.”

He walked over to the windows, examining each of them in turn.

“And again—nothing. Not even a balcony outside.”

“Even if there were,” said the inspector impatiently, “I don’t see how that would help us, if the maid never left the room.”

Évidemment,” said Poirot, not disconcerted. “As Mademoiselle is positive she did not leave the room——”