Poirot answered them categorically—almost mechanically.
“Who? That is the question. Why? Ah, if I only knew. When? Since I was here an hour ago. As to the door being locked, it is a very ordinary lock. Probably any other of the doorkeys in this passage would fit it.”
We stared at one another blankly. Poirot had walked over to the mantelpiece. He was outwardly calm, but I noticed his hands, which from long force of habit were mechanically straightening the spill vases on the mantelpiece, were shaking violently.
“You do not agree? But such things have been. Well, we will come in and interview the brave Dorcas.”
Dorcas was standing in the boudoir, her hands folded in front of her, and her grey hair rose in stiff waves under her white cap. She was the very model and picture of a good old-fashioned servant.