"DRINK?"

McGreavy shook his head moodily, studying Judd. Judd poured himself his second stiff scotch while McGreavy watched without comment. Judd's hands were still trembling. As the warmth of the whiskey floated through him, he felt himself beginning to relax.

McGreavy had arrived at the office two minutes after the lights had come on. With him was a stolid police sergeant who now sat making notes in a shorthand notebook.

McGreavy was talking. "Let's go over it once more, Dr. Stevens."

Judd took a deep breath and began again, deliberately keeping his voice calm and low. "I locked the office and went to the elevator. The corridor lights blacked out. I thought that the lights on the lower floors might be working, and I started to walk down." Judd hesitated, reliving the fear. "I saw someone coming up the stairs with a flashlight. I called out. I thought it was Bigelow, the guard. It wasn't."

"Who was it?"

"I've told you," said Judd. "I don't know. They didn't answer."

"What made you think they were coming to kill you?"

An angry retort came to Judd's lips, and he checked it. It was essential to make McGreavy believe him. "They followed me back to my office."

"You think there were two men trying to kill you?"

"At least two," Judd said. "I heard them whispering."

"You said that when you entered your reception office, you locked the outside door leading to the corridor. Is that right?"

"Yes."

"And that when you came into your inner office, you locked the door leading to the reception office."

"Yes."

McGreavy walked over to the door leading from the reception office to Judd's inner office. "Did they try to force this door?"

"No," admitted Judd. He remembered how puzzled he had been by that.

"Right," said McGreavy. "When you lock the reception-office door that opens onto the corridor, it takes a special key to open it from the outside."

Judd hesitated. He knew what McGreavy was leading up to. "Yes."

"Who had the keys to that lock?"

Judd felt his face reddening. "Carol and I."

McGreavy's voice was bland. "What about the cleaning people? How did they get in?"

"We had a special arrangement with them. Carol came in early three mornings a week and let them in. They were finished before my first patient arrived."

"That seems inconvenient. Why couldn't they get into these offices when they cleaned all the other offices?"

"Because the files I keep in here are of a highly confidential nature. I prefer the inconvenience to having strangers in here when no one is around."

McGreavy looked over at the sergeant to make sure he was getting it all down. Satisfied, he turned back to Judd. "When we walked into the reception office, the door was unlocked. Not forced - unlocked."

Judd said nothing.

McGreavy went on. "You just told us that the only ones who had a key to that lock were you and Carol. And we have Carol's key. Think again, Dr. Stevens. Who else had a key to that door?"

"No one."

"Then how do you suppose those men got in?"

And Judd suddenly knew. "They made a copy of Carol's key when they killed her."

"It's possible," conceded McGreavy. A bleak smile touched his lips. "If they made a copy, we'll find paraffin traces on her key. I'll have the lab run a test."

Judd nodded. He felt as though he had scored a victory, but his feeling of satisfaction was short-lived.

"So the way you see it," McGreavy said, "two men - we'll assume for the moment there's no woman involved - had a key copied so they could get into your office and kill you. Right?"

"Right," said Judd.

"Now you said that when you went into your office, you locked the inner door. True?"

"Yes," Judd said.

McGreavy's voice was almost mild. "But we found that door unlocked, too."

"They must have had a key to it."

"Then after they got it open, why didn't they kill you?"

"I told you. They heard the voices on the tape and - "

"These two desperate killers went to all the trouble to knock out the lights, trap you up here, break into your office - and then just vanished into thin air without harming a hair of your head?" His voice was filled with contempt.

Judd felt cold anger rising in him. "What are you implying?"

"I'll spell it out for you, Doctor. I don't think anyone was here and I don't believe anyone tried to kill you."

"You don't have to take my word for it," Judd said angrily. "What about the lights? What about the night watchman, Bigelow?"

"He's in the lobby."

Judd's heart missed a beat. "Dead?"

"He wasn't when he let us in. There was a faulty wire in the main power switch. Bigelow was down in the basement trying to fix it. He got it working just as I arrived."

Judd looked at him numbly. "Oh," he said finally.

"I don't know what you're playing at, Dr. Stevens," McGreavy said, "but from now on, count me out." He moved toward the door. "And do me a favor. Don't call me again - I'll call you."

The sergeant snapped his notebook shut and followed McGreavy out.

The effects of the whiskey had evaporated. The euphoria had gone, and he was left with a deep depression. He had no idea what his next move should be. He was on the inside of a puzzle that had no key. He felt like the boy who cried "wolf," except that the wolves were deadly, unseen phantoms, and every time McGreavy came, they seemed to vanish. Phantoms or...There was one other possibility. It was so horrifying that he couldn't bring himself to even acknowledge it. But he had to.

He had to face the possibility that he was a paranoiac.

A mind that was overstressed could give birth to delusions that seemed totally real. He had been working too hard. He had not had a vacation in years. It was conceivable that the deaths of Hanson and Carol could have been the catalyst that had sent his mind over some emotional precipice so that events became enormously magnified and out of joint. People suffering from paranoia lived in a land where everyday, commonplace things represented nameless terrors. Take the car accident. If it had been a deliberate attempt to kill him, surely the driver would have gotten out and made sure that the job was finished. And the two men who had come here tonight. He did not know that they had guns. Would a paranoiac not assume that they were there to kill him? It was more logical to believe that they were sneak thieves. When they had heard the voices in his inner office, they had fled. Surely, if they were assassins, they would have opened the unlocked door and killed him. How could he find out the truth? He knew it would be useless to appeal to the police again. There was no one to whom he could turn.

An idea began to form. It was born of desperation, but the more he examined it, the more sense it made. He picked up the telephone directory and began to riffle through the yellow pages.