Bolton shook his head.

"No," he answered; "it looks just the same to me--except, as I say,
that the door seemed to open more easily."

"H'm," muttered Gatton; "and you carried the keys in your pocket until
you went off duty?"

"Yes, sir."

"All right. You can go now."

Bolton touched his bowler and departed, and Gatton turned to me with a
grim smile.

"We'll just step inside again," he said, "so as not to attract any
undue attention."

He again unlocked the garage door and closed it as we entered.

"Now," said he, "before we go any further what was your idea in
keeping back the fact that one of the missing links in the chain of
evidence was already in your possession?"

"No doubt," I said rather guiltily, "you refer to the fact of my
acquaintance with Miss Isobel Merlin?"

"I do!" said Gatton, "and to the fact that you nipped in ahead of me
and interviewed this important witness before I had even heard of her