“Good afternoon, sir; it was lucky you came along with me last night.  I thought it was a funny go and I was right, it seems.”

“Quite right,” said Gatton shortly, “and now here are the keys which you returned to the depot this morning.”

From his pocket the Inspector produced a steel ring bearing a large and a small key which I recognized as that which had hung from the lock of the garage door on the previous night.

We walked along to the garage and Inspector Gatton placed the key in the lock; then turning to Bolton: 

“Now,” he directed, “show us exactly what you did.”

Bolton replaced his bowler, which hitherto he had carried in his hand, hesitated for a moment, and then unlocked the door.

“Of course I had my lantern with me last night,” he explained, “and this gentleman and myself stood looking in for a moment.”

“Mr. Addison has already described to me exactly what he saw,” said Gatton.  “Show us what you did after Mr. Addison left you.”

Bolton, with a far-away look in his eyes betokening an effort of retrospection, withdrew the key from the lock and entered the garage, Gatton and I following.  There was a sky window to light the place, so that when Bolton reclosed the door we could see well enough.  His movements were as follows:  Relocking the door from the inside, he walked slowly along to a smaller door at the opposite end and with the other key attached to the ring unfastened it.

“Wait a moment,” said Gatton.  “Did you look about you at all before opening this door?”

“Only long enough to find where it was, sir.  Just about as long as I showed you.”

“All right.  Go on, then.”

We followed Bolton out into a very narrow hedge-bordered path, evidently a tradesman’s entrance, and he turned and locked the door behind him.  Slipping the keys into his pocket, he tramped stolidly out to the main road whereon we emerged immediately beside the garage.

“Ah,” murmured Gatton.  “Now give me the keys,” and as the man did so:  “Throughout all this time did you see or hear anything of an unusual nature?”

Bolton removed his bowler once more.  I had gathered by this time that he regarded fresh air as an aid to reflection.

“Well, sir,” he replied in a puzzled way, “that first door—­”

“Well,” said Gatton, as the man hesitated.

“It seemed to open more easily just now than it did last night.  There seemed to be a sort of hitch before when it was about half-way open.”

“Perhaps the crate was in the way?” suggested Gatton.  “Except for the absence of the crate do you notice anything different, anything missing, or anything there now that was not there before?”

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?”