“All the exits having been guarded or locked, and the alley having been under constant surveillance from 9:35 on by Lynch, Elinor, Johnny Chase—the usher—and after him the police—these being the facts, all my questioning and checking, gentlemen,” continued Ellery in a grave tone, “lead to the inevitable conclusion that, from the time the murder was discovered and all the time thereafter while the investigation was going on, _the murderer was in the theatre!_” A silence followed Ellery’s pronouncement. “Incidentally,” he added calmly, “it occurred to me when I talked to the ushers to ask if they had seen any one leave his seat after the second act started, and they can’t recall anyone changing seats!” Queen idly took another pinch of snuff. “Nice work—and a very pretty piece of reasoning, my son—but nothing, after all, of a startling or conclusive nature. Granted that the murderer was in the theatre all that time—how could we possibly have laid our hands on him?” “He didn’t say you could,” put in Sampson, smiling. “Don’t be so sensitive, old boy; nobody’s going to report you for negligence in the performance of your duty. From all I’ve heard to-night you handled the affair well.” Queen grunted. “I’ll admit I’m a little peeved at myself for not following up that matter of the doors more thoroughly. But even if it were possible for the murderer to have left directly after the crime, I nevertheless would have had to pursue the inquiry as I did, on the chance that he was still in the theatre.” “But dad—of course!” said Ellery seriously. “You had so many things to attend to, while all I had to do was stand around and look Socratic.” “How about the people who have come under the eye of the investigation so far?” asked Sampson curiously.