There was a comfortable silence as the Inspector sprawled in the light of the leaping flames. Ellery munched contentedly on a succulent piece of pastry. Djuna’s bright eyes gleamed from the far corner of the room, where he had stolen noiselessly and squatted on his thin haunches on the floor, listening to the conversation. Suddenly the old man’s eyes met Ellery’s in a spasmodic transference of thought. “The hat....” muttered Queen. “We always come back to the hat.” Ellery’s glance was troubled. “And not a bad thing to come back to, dad. Hat—hat—hat! Where does it fit in? Just what do we know about it?” The Inspector shifted in his chair. He crossed his legs, took another pinch of snuff and proceeded with a fresh vigor. “All right. We can’t afford to be lazy in the matter of that blamed silk-topper,” he said briskly. “What do we know so far? First, that the hat did not leave the theatre. It seems funny, doesn’t it? Doesn’t seem possible that we would find no trace at all after such a thorough search.... Nothing was left in the cloak-room after everybody was gone; nothing was found in the sweepings that might indicate a hat torn to small pieces or burned; in fact, not a trace, not a thing for us to go on. Therefore, Ellery, the only sensible conclusion we can make at this point is _that we haven’t looked for the hat in the right place_! And further, wherever it is, it’s still there, due to our precaution of closing the theatre down since Monday night. Ellery, we’ve got to go back to-morrow morning and turn that place upside down. I won’t sleep until we see light somewhere in this matter.” Ellery was silent. “I’m not at all satisfied with things as you’ve stated them, dad,” he muttered at last. “Hat—hat—there’s something wrong somewhere!” He fell silent once more. “No! The hat is the focal point of this investigation—I cannot see any other way out of it. Solve the mystery of Field’s hat and you will find the one essential clue that will point to the murderer. I’m so convinced of this that I’ll be satisfied we’re on the right track only when we’re making progress in the explanation of the hat.” The old man nodded his head vigorously. “Ever since yesterday morning, when I had time to think over the hat business, I’ve felt that we had gone astray somewhere. And here it is Wednesday night—still no light. We’ve done necessary things—they’ve led nowhere....” He stared into the fire. “Everything is so badly muddled. I’ve got all the loose ends at my fingertips, but for some blasted reason I can’t seem to make them cohere—fit together—_explain_ anything.... Undoubtedly, son, what is missing is the story of the top-piece.” The telephone bell rang. The Inspector sprang for the instrument. He listened attentively to a man’s unhurried tones, made a brisk comment and finally hung up. “Who’s the latest midnight babbler, O recipient of many confidences?” asked Ellery, grinning.