Discovery of the Weapon

The discovery of the weapon in Mrs. Hubbard's sponge-bag provides a crucial piece of physical evidence that initially seems to confirm the theory of a single intruder but ultimately deepens the mystery, as Poirot's reaction reveals his growing suspicion that the clues are being deliberately manipulated.

Discovery and Immediate Reaction

Mrs. Hubbard burst into the dining-car in a state of extreme agitation, crying out, "It's too horrible! It's just too horrible. In my sponge-bag. My sponge-bag! A great knife—all over blood?" before fainting heavily on M. Bouc's shoulder. Dr. Constantine, with more vigour than chivalry, deposited the fainting lady with her head on the table and yelled for an attendant, then hurried off after the other two men, his interest lying wholly in the crime rather than in swooning middle-aged ladies. Poirot, M. Bouc, and Dr. Constantine rushed to Mrs. Hubbard's compartment, where they found the conductor keeping back a crowd of curious passengers. Hanging on the handle of the door that gave access to the next compartment was a large-checked rubber sponge-bag, and below it on the floor, just where it had fallen from Mrs. Hubbard's hand, lay a straight-bladed dagger—a cheap affair, sham Oriental with an embossed hilt and a tapering blade stained with patches of what looked like rust.

Examination of the Weapon

Poirot picked up the dagger delicately and murmured, "Yes, there is no mistake. Here is our missing weapon all right—eh, doctor?" Dr. Constantine examined it and confirmed, "It is the weapon all right. It would account for any of the wounds." Poirot immediately cautioned against jumping to conclusions, imploring the doctor not to say that, because they were already "heavily overburdened by coincidence" and it would be "too much of a good thing that both of them should select the same weapon." The doctor pointed out that thousands of these sham Eastern daggers were made and shipped to the bazaars of Constantinople, so the coincidence was not as great as it seemed. Poirot then looked thoughtfully at the communicating door, lifted off the sponge-bag, and tried the handle, but the door did not budge. He drew back the bolt and tried again, but still the door remained fast, until Dr. Constantine reminded him that they had locked it from the other side.

Poirot's Perplexity

M. Bouc offered a straightforward reconstruction: the murderer passed through Mrs. Hubbard's carriage, shut the communicating door behind him, felt the sponge-bag, slipped the blood-stained knife inside, and then slipped out through the other door into the corridor, all unwitting that he had awakened Mrs. Hubbard. Poirot murmured agreement, saying, "As you say. That is how it must have happened," but the puzzled look did not leave his face. When M. Bouc demanded to know what was troubling him, Poirot replied, "The same point does not strike you? No, evidently not. Well, it is a small matter." This moment of hesitation—the first crack in the seemingly neat narrative—foreshadows Poirot's later realization that the clues, including the weapon, have been planted as part of an elaborate conspiracy. The dagger itself, a cheap mass-produced item, is a deliberately chosen prop, not a personal weapon, and its placement in the sponge-bag is too convenient to be genuine. The discovery of the weapon, far from solving the crime, becomes another piece of the puzzle that Poirot must fit into his larger theory of a collective execution.