"He did come in a few minutes ago, and took a small leather case, but he went out again at once."
"Went out? You saw him?"
"Yes. He was coming out just as I came in, sir," replied the girl.
"Gone!" I gasped, turning to the ex-sergeant.
"He must have gone down the stairs, sir," the man suggested.
With a glance round the room, which only contained a suit-case, I dashed down the stairs and into the hall.
Of the porter at the door I asked a quick question.
"No, sir," he replied. "Mr. Vernon hasn't gone out this way. He may have gone out by the door in Whitehall Place."
I rushed through the hotel and, at the door indicated, the man in uniform told me that Mr. Vernon had left on foot five minutes before, going towards Whitehall.
I hurried after him, but alas! I was too late.