They returned to the library and he sat down before the table again, but just as he was going to pick up the pen a thought seemed to strike him.
"By the way," he said, "I remember hearing something about the loss of a ring. The burglar didn't take that, did he?"
"Oh, no, sir, I remember the advertisement was in the paper before the night of the burglary."
He opened his eyes and then smiled.
"Brilliant police you've got!" he murmured, and took up the pen again.
"There was another burglar here and he might have taken it!" said Mary in a low voice.
The visitor once more dropped the pen and looked up with a start.
"Another burglar!" he exclaimed.
"Well, sir, this one didn't actually burgle, but—"