She was not in much doubt. The button was of a quite peculiar kind—a bright brass button identical with those which George Brooklyn always wore on his summer evening coat. Here was luck indeed. According to her theory Carter Woodman had been mistaken for George Brooklyn because he had deliberately come out of Liskeard House wearing George’s coat and opera hat. George was very particular with his dress, and the coat was quite unmistakable. With these, if not in them, he must have returned to the Cunningham Hotel, where he would have stowed them away somewhere safely for the night. But the next morning his first object would be to get rid of their incriminating presence. She had guessed that he would pack them away in the bag which he usually carried, and so leave for the office bearing them away without any risk of arousing suspicion. Then her first thought had been that he would leave them in some railway cloak-room, or drop them quietly into the river. But this would involve the risk that the bag might turn up, and be identified as his. What would be the safest way of disposing of the hat and coat without leaving the bag, or running any risk of identification? She thought she had guessed at least one way in which it might have been done, and it was to follow this up that she wanted Ellery’s help. She had now proved definitely to her own satisfaction that the coat had been in Woodman’s bag; but she was not sure whether the police would be willing to accept the evidence of a solitary coat-button. They must find the coat, unless it had been put beyond reach of recovery. When Ellery arrived Joan told him that they were going to lunch together at the Avenue Restaurant opposite Hatton Garden. In a few words she told him what he was to do. At the Avenue Joan remained at the table they had chosen, while Ellery went to the gentlemen’s cloak room. There was no attendant in the room at the time, and Ellery made a quick survey of the two or three dozen hats and coats which were hanging there. What he was looking for was at any rate not among them. In a few minutes the attendant came in, and Ellery entered into talk. “Do you get many hats and coats left behind here?” he asked. “Not many, sir. Sometimes a gentleman leaves a coat or an umbrella; but he generally comes back for it. Gentlemen sometimes leave things when they’re a bit on, sir, if I may put it so without taking a liberty. But not often, sir. Most of the customers here are very regular gents. When things is left we keep them here for a week or two and then we send them to the Lost Property Office. Have you lost something, sir?” “No, but a friend of mine thinks he left a coat and opera hat here a week or so ago. Have you found anything of the sort?”