Poirot, Bouc, and Dr. Constantine discuss the case. Poirot notes that they learned from MacQueen that Mr. Ratchett (Cassetti) spoke no French. However, Poirot heard someone from Mr. Ratchett (Cassetti)’s room speak in French to the conductor in the night; this suggests someone else was in the room—a possible murderer. This will be revealed as a false clue, designed to lead Poirot to believe that there was a francophone stranger in the room.

Poirot asks, “Are these people whose evidence we have taken speaking the truth or lying?” (201). He makes a list of the 12 people he’s interviewed; for each one, he writes out the motive, alibi, evidence against them, and suspicious circumstances.

Poirot continues his discussion with Bouc and Dr. Constantine, presenting them with a list of 10 questions—things that require explanation. Points of confusion include who the handkerchief marked “H” belongs to; who the pipe-cleaner belongs to; who wore the scarlet kimono; who was masquerading as a conductor in a Wagon Lit uniform; why the hands of the watch on Mr. Ratchett (Cassetti)’s body point to 1:15; when the murder was committed; and whether it’s certain that Mr. Ratchett (Cassetti) was stabbed by more than one person. Poirot concludes, “One or more of those passengers killed Ratchett.