Heath was almost contemptuous in his reply. “Didn’t the guy wear gloves, and use a jimmy? It was a yeggman’s job, all right.”

CHAPTER VIII.
The Invisible Murderer

(Tuesday, September 11; 11.45 a. m.)

Markham went to the window and stood, his hands behind him, looking down into the little paved rear yard. After several minutes he turned slowly.

“The situation, as I see it,” he said, “boils down to this:—The Odell girl has an engagement for dinner and the theatre with a man of some distinction. He calls for her a little after seven, and they go out together. At eleven o’clock they return. He goes with her into her apartment and remains half an hour. He leaves at half past eleven and asks the phone operator to call him a taxi. While he is waiting the girl screams and calls for help, and, in response to his inquiries, she tells him nothing is wrong and bids him go away. The taxi arrives, and he departs in it. Ten minutes later some one telephones her, and a man answers from her apartment. This morning she is found murdered, and the apartment ransacked.”

He took a long draw on his cigar.

“Now, it is obvious that when she and her escort returned last night, there was another man in this place somewhere; and it is also obvious that the girl was alive after her escort had departed. Therefore, we must conclude that the man who was already in the apartment was the person who murdered her. This conclusion is further corroborated by Doctor Doremus’s report that the crime occurred between eleven and twelve. But since her escort did not leave till half past eleven, and spoke with her after that time, we can put the actual hour of the murder as between half past eleven and midnight. . . . These are the inferable facts from the evidence thus far adduced.”

“There’s not much getting away from ’em,” agreed Heath.

“At any rate, they’re interestin’,” murmured Vance.

Markham, walking up and down earnestly, continued: