"I think it was about three months ago," said Colin, after a moment's reflection. "I wasn't here at the time; in fact, there was no one else in the house except Mrs. Ramsay and the cook. That was really the chief reason why the Professor decided to engage an assistant."
"Why weren't the police notified?" demanded the Inspector. "There was certainly no report sent in to the Yard."
"The Professor declared that he didn't want to waste his time. He was a very busy man, and as nothing appeared to have been stolen he decided to let the whole matter drop."
"Nothing stolen!" repeated Marsden, raising his eyebrows. "Are you perfectly certain about that?"
"It's what he told me, anyhow," replied Colin. "According to him, the only damage they did was to smash open his desk and search his papers."
Both men glanced across the room in the direction of the oak bureau.
"Is that the desk?" inquired the Sergeant.
Colin nodded.
"Had he any idea what they were after?"
"Not the slightest. All his papers which are of any scientific value are kept in the laboratory. I believe he had some money and valuables in the safe, but they seem to have left that entirely alone."