It would not take a minute. Then he would be safe and later when the body was found what could they prove? The others had been out of the room too.

But as he touched the knife it began to happen. Something came from the blade up his arm and into his head. He was in a hurry, there was no time—but holding the knife, the color of things began to change.

He was half-naked when Marshall found him.

Sister Ursula leaned against the jamb of the kitchen door. She felt sick. Marshall and Raglan were both strong men, but they needed help to subdue him. His face was contorted into an unrecognizable mask like a demon from a Japanese tragedy. She clutched the crucifix of the rosary that hung at her waist and murmured a prayer to the Archangel Michael. For it was not the physical strength of the man that frightened her, nor the glint of his knife, but the pure quality of incarnate evil that radiated from him and made the doctrine of possession a real terror.

As she finished her prayer, Marshall’s fist connected with his jaw and he crumpled. So did Sister Ursula.

“I don’t know what you think of me,” Sister Ursula said as Marshall drove her home. (Sister Felicitas was dozing in the backseat.) “I’m afraid I couldn’t ever have been a policewoman after all.”

“You’ll do,” Marshall said. “And if you feel better now, I’d like to run over it with you. I’ve got to get my brilliant deductions straight for the press.”

“The fresh air feels good. Go ahead.”

“I’ve got the sheet business down pat, I think. In ordinary middle-class households you don’t change both sheets every week; Leona never does, I remembered. You put on a clean upper sheet, and the old upper becomes the lower. The other three bedrooms each had one clean sheet—the upper. His had two—upper and lower; therefore his upper sheet had been stained in some unusual way and had to be changed. The hasty bath, probably in the dark, had been careless, and there was some blood left to stain the sheet. Mrs. Carey wouldn’t have thought anything of it at the time because she hadn’t found the body yet. Right?”

“Perfect, Lieutenant.”

“So. But now about Quasimodo . . . I still don’t get it. He’s the one it couldn’t apply to. Either of the others—”

“Yes?”

“Well, who is Quasimodo? He’s the Hunchback of Notre Dame. So it could mean the deformed de’Cassis. Who wrote Quasimodo? Victor Hugo. So it could be Hugo Ellis. But it wasn’t either; and how in heaven’s name could it mean Professor Lowe?”