“In a box, Miss Rivers. There is not, I believe, very much accommodation for sitting out anywhere else at the Albert Hall.”

“Except outside in one's car,” she replied.

“Hush, misguided child!” said Kenneth. “The most elementary methods will discover that my car went to Hornet's Garage to be de-coked yesterday. Am I not right, Superintendent?”

“Quite,” said Hannasyde. “And am I not right, Mr Vereker, in saying that you left the Albert Hall by the main entrance at twenty minutes past ten, and returned just before eleven?”

“Pausing on both occasions to exchange a few words with the commissionaire,” added Kenneth, still at work on his sketch. “Thus doing what I could to stamp myself on his memory. The question which is worrying you at the moment is, of course, Am I diabolically cunning, or incredibly stupid?”

“Don't pay any attention to him!” Leslie said quickly. “This is all nonsense - every word of it! He didn't leave the Albert Hall until we came away after four o'clock, together.”

Kenneth tossed the sketch aside. “My dear girl, do, do dry up! I'm sick of this involved story, anyway, but don't you realise that at any moment now my friend-the Superintendent is going to produce that commissionaire out of his hat to identify me?” He glanced at Hannasyde. “Well, my friend, produce him! Let it be admitted that I did leave the Albert Hall during the course of the evening. It does not follow that I went to my halfbrother's flat, and you know it. You have - as they say in American films - nothing on me.”

“Oh, yes, I have, Mr Vereker,” replied Hannasyde quietly.

Kenneth looked contemptuous. “One pipe, which I may have left in Roger's flat four nights ago.”

“Not only your pipe. An automatic pistol also.”