“The quick brain, Henry, the quick brain,” said Queen gravely. “It has run many a man’s neck into the noose.... As he made the lightning decision to take the hat, he realized that he could not leave his own in its place. For one thing, his hat was a snap-down—an opera-hat— but more important, it had the name of Le Brun, the theatrical costumer, stamped in it. You can see that this would immediately point to someone in the cast—just the thing he wished to avoid. He told me also that at the moment, and for quite some time thereafter, he felt that the most the police could deduce from the hat’s being missing was that it was taken because it contained something valuable. He could not see how this investigatory guess would point the finger of suspicion anywhere near him. When I explained to him the series of deductions Ellery made from the mere fact that the tophat was missing, he was utterly astounded.... You can see, now, that the only really fundamental weakness of his crime was due not to an oversight or a mistake on his part, but to an occurrence which he could not possibly have foreseen. It forced his hand and the entire chain was started. Had Barry’s name not been lettered in Field’s hat, there is no question in my mind but that he would be a free and unsuspected man to-day. The police records would carry another unsolved murder on its pages. “I need not state that this entire train of thought flashed through his brain in less time than it takes to describe. He saw what he had to do and his plans adjusted themselves instantly to the new development.... When Field extracted the papers from the hat, Barry examined them cursorily under the lawyer’s watchful eye. He did this by the same pencil flashlight—a tiny streak of illumination quite obscured by their shielding bodies. The papers seemed in good order and complete. But Barry did not spend much time over the papers at the moment. He looked up with a rueful smile and said: ‘Seem to be all here, damn you’—very naturally, as if they were enemies under a truce and he was being a good sport. Field interpreted the remark for what it was intended to convey. Barry dipped into his pocket—the light was out now—and, as if he were nervous, took a swig at a pocket-flask of good whisky. Then as if recollecting his manners, he asked Field pleasantly enough if he would not take a drink to bind the bargain. Field, having seen Barry drink from the flask, could have no suspicion of foul play. In fact, he probably never dreamed that Barry would try to do him in. Barry handed him a flask....