"I should say Gilson's idea was to get the key, hence the murder."
"And while he was strangling Peter, what was Simon doing? Since Peter was found in the sitting-room in his pajamas, it is permissible to suppose that something had aroused him. If it did not arouse Simon too, Peter would be likely to do so, and at the very least he would have called for help the moment he was attacked."
"You forget the doctor's evidence," I said. "He was killed by the shock as much as by the man's fingers at his throat."
"A most important point," said Quarles; "we will come back to it in a minute. Having murdered both the Judds, this imbecile breaks into the shed, because he fails to find the key, I suppose; and having got the money, is satisfied. He hides one body and leaves the other. He lays a false trail for no earthly reason, I submit. For months he does not let fall a word to disturb his mother, but he haunts the gate of the farm."
"His mother knows he is guilty, professor; remember that."
"Did she see him do it? Has he shown her the money?"
"No."
"Then, I ask, what made Gilson haunt the farm? The right answer to that question will put you on the right road. It was Zena who propounded that question to me."
"In seeking for motives we must not be too precise in dealing with a madman," I said. "I think his idea was to protect the money which he had hidden somewhere close at hand."
"I don't," said Quarles. "He was watching for the man who murdered Peter Judd."