"The rooms are locked?" asked Poirot.
"Dr. Bauerstein considered it advisable."
Poirot nodded thoughtfully.
"Then he is very sure. Well, that simplifies matters for us."
We went up together to the room of the tragedy. For convenience I append a plan of the room and the principal articles of furniture in it.
Poirot locked the door on the inside, and proceeded to a minute inspection of the room. He darted from one object to the other with the agility of a grasshopper. I remained by the door, fearing to obliterate any clues. Poirot, however, did not seem grateful to me for my forbearance.