"Positive! In what way?"
"It seems that he and one of the other clerks required to move the box yesterday. And he maintains that one or other of them, or both, must have seen the secret chamber if it had been open then. He concludes, of course, that it has been opened since he saw it last. His theory is that it was opened last night by a burglar. I don't know whether he really believes that; it appears preposterous and beyond possibility that any ordinary burglar would be acquainted with this secret chamber."
Gilbert nodded his agreement. He had listened carefully to his father, but at the same time had been trying to understand how the mechanism was worked by which the chamber was opened and closed. It baffled him, however, and he desisted from the attempt.
"What do you make of it?" asked the father.
"Do you believe Whittaker right in thinking the chamber was opened last night?" inquired Gilbert.
"I do."
"But that he was wrong in putting it down to a burglar?"
"Yes. Do burglars break into lawyer's rooms? I don't mean to say that such a thing is impossible, for valuable documents have been stolen—you can imagine that."
"Of course. But if the secret chamber was not opened by a burglar, then by whom was it opened?"
"That is the question," said Eversleigh, gazing earnestly at his son.