"Exactly. But surely it was not possible for anyone to touch them while you were working in the room. Constance, what do you say? You should be the best judge of that."
Salome raised her eyes frankly to the Principal. "I have been thinking of that, Miss St. Leger. It seems quite impossible to me. I did not leave my place after the weighing till we went out about ten minutes later."
"And the nearest girls to you?"
"Eileen and Duane, and they were right at the farther ends of the benches. I am quite sure no girl in this room touched them then."
"Who was the last one to leave the room?"
"Eileen and I. We came out together with Miss Vacher."
"You are quite sure of that? No one was left behind, even for a half minute or so? It could have been done in a few seconds."
"I was the last out, Miss St. Leger," replied the science mistress, "and I locked the door after me."
"Most extraordinary," said the Principal, "and there is only one key to that lock in the school. We found that out last year. The key never left your possession during the dinner hour, I suppose, Miss Vacher?"
The science mistress was looking far from happy. "The key was not in my possession, Miss St. Leger. After last year—I mean, owing to my unfortunate absent-mindedness—I decided to entrust it to somebody else. Duane took charge of it for me."