Crossing the studio again, they entered the Billiard Room, a large apartment with seats round the walls and the table in the centre.

Cue racks and much smoking and other masculine paraphernalia were all about. There were a skylight of stained glass and a few high side windows. An outside door was on the South side.

“Here Mr. Courtenay left Mrs. Stannard, at much the same time Barry left the girl,” Roberts said. “So you see, Steele, their chances are equal.”

“Chances of what?”

“I mean chances to go into the studio, unobserved of anybody, commit the deed, turn off the lights, and then, either return to the spot she came from or to remain in the room until the other entered. It must have been that way, for there’s no other way for it to be.”

“All right; now, what about Mrs. Stannard’s story of overhearing the stuff her husband said to the girl?”

“Probably true, but if he said that to Miss Vernon and Mrs. Stannard overheard it, she might have run in and found the dead man, or she might have run in and stabbed the living man.”

“In the dark?”

“Perhaps so. She knew where every bit of furniture was. But isn’t it quite as likely that the girl did the stabbing?”

“That wax baby?”