UDD STOOD IN FRONT of the elevator, the wave of darkness lapping at him like a physical force. He could feel his heart slow and then begin to beat faster. A sudden, atavistic fear flooded his body, and he reached in his pockets for a book of matches. He had left them in the office. Perhaps the lights were working on the floors below. Moving slowly and cautiously, he groped his way toward the door that led to the stairwell. He pushed the door open. The stairwell was in darkness. Carefully holding onto the railing, he started down into the blackness. In the distance below, he saw the wavering beam of a flashlight moving up the stairs. He was filled with sudden relief. Bigelow, the watchman. "Bigelow!" he yelled. "Bigelow! It's Dr. Stevens!" His voice bounced against the stone walls, echoing eerily through the stairwell. The figure holding the flashlight kept climbing silently, inexorably upward. "Who's there?" Judd demanded. The only answer was the echo of his words.

And Judd suddenly knew who was there. His assassins. There had to be at least two of them. One had cut off the power in the basement while the other blocked the stairs to prevent his escape.

The beam of the flashlight was coming closer, only two or three floors below now, climbing rapidly. Judd's body went cold with fear. His heart began to pound like a trip-hammer, and his legs felt weak. He turned quickly and went back up the stairs to his floor. He opened the door and stood, listening. What if someone were waiting up here in the dark corridor for him?

The sounds of the footsteps advancing up the stairs were louder now. His mouth dry, Judd turned and made his way along the inky corridor. When he reached the elevators, he began counting office doors. As he reached his office, he heard the stairwell door open. The keys slipped from his nervous fingers and dropped to the floor. He fumbled for them frantically, found them, opened the door to his reception room, and went in, double-locking the door behind him. No one could open it now without a special key.

From the corridor outside, he could hear the sound of approaching footsteps. He went into his private office and flicked the light switch. Nothing happened. There was no power at all in the building. He locked the inner door, then moved to the phone. He fumbled for the dial and dialed the operator. There were three long, steady rings, and then the operator's voice, Judd's only link to the outside world.

He spoke softly. "Operator, this is an emergency. This is Dr. Judd Stevens. I want to speak to Detective Frank Angeli at the Nineteenth Precinct. Please hurry!"

"Thank you. Your number please?"

Judd gave it to her.

"One moment, please."

He heard the sound of someone testing the corridor entrance to his private office. They could not get in that way because there was no outside knob on the door.

"Hurry, Operator!"

"One moment, please," replied the cool, unhurried voice.

There was a buzz on the line and then the police switchboard operator spoke. "Nineteenth Precinct."

Judd's heart leaped. "Detective Angeli," he said. "It's urgent!"

"Detective Angeli...just a moment, please."

Outside in the corridor, something was happening. He could hear the sound of muted voices. Someone had joined the first man. What were they planning?

A familiar voice came on the phone. "Detective Angeli's not here. This is his partner, Lieutenant McGreavy. Can - "

"This is Judd Stevens. I'm in my office. The lights are all out and someone's trying to break in and kill me!"

There was a heavy silence on the other end. "Look, Doctor," said McGreavy. "Why don't you come down here and we'll talk a - "

"I can't come down there," Judd almost shouted. "Someone's trying to murder me!"

There was another silence at the other end of the line. McGreavy did not believe him and was not going to help him. Outside, Judd heard a door open, and then the sound of voices in the reception office. They were in the reception office! It was impossible for them to have gotten in without a key. But he could hear them moving, coming toward the door to his private office.

McGreavy's voice was coming over the phone, but Judd did not even listen. It was too late. He replaced the receiver. It would not have mattered even if McGreavy had agreed to come. The assassins were here! Life is a very thin thread and it only takes a second to snap it. The fear that gripped him turned to a blind rage. He refused to be slaughtered like Hanson and Carol. He was going to put up a fight. He felt around in the dark for a possible weapon. An ashtray...a letter opener...useless. The assassins would have guns. It was a Kafka nightmare. He was being condemned for no reason by faceless executioners.

He heard them moving closer to the inner door and knew that he only had a minute or two left to live. With a strange, dispassionate calm, as though he were his own patient, he examined his final thoughts. He thought of Anne, and a sense of aching loss filled him. He thought of his patients, and of how much they needed him. Harrison Burke. With a pang he remembered that he had not yet told Burke's employer that Burke had to be committed. He would put the tapes where they could be...His heart lurched. Perhaps he did have a weapon to fight with!

He heard the doorknob turning. The door was locked, but it was flimsy. It would be simple for them to break it in. He quickly groped his way in the dark to the table where he had locked away Burke's tape. He heard a creak as pressure was applied against the reception-room door. Then he heard someone fumbling at the lock. Why don't they just break it down? he thought. Somewhere, far back in his mind, he felt the answer was important, but he had no time to think about it now. With trembling fingers he unlocked the drawer with the tape in it. He ripped it out of its cardboard container, then moved over to the tape player and started to thread it. It was an outside chance, but it was the only one he had.

He stood there, concentrating, trying to recall his exact conversation with Burke. The pressure on the door increased. Judd gave a quick, silent prayer. "I'm sorry about the power going out," he said aloud. "But I'm sure they'll have it fixed in a few minutes, Harrison. Why don't you lie down and relax?"

The noise at the door suddenly ceased. Judd had finished threading the tape into the player. He pressed the "on" button. Nothing happened. Of course! All the power in the building was off. He could hear them begin to work on the lock again. A feeling of desperation seized him. "That's better," he said loudly. "Just make yourself comfortable." He fumbled for the packet of matches on the table, found it, tore out a match and lit it. He held the flame close to the tape player. There was a switch marked "battery." He turned the knob, then pressed the "on" button again. At that moment, there was a sudden click as the lock on the door sprung open. His last defense was gone!

And then Burke's voice rang through the room. "Is that all you've got to say? You don't even want to hear my proof. How do I know you're not one of them?"

Judd froze, not daring to move, his heart roaring like thunder.

"You know I'm not one of them," said Judd's voice from the tape. "I'm your friend. I'm trying to help you... Tell me about your proof."

"They broke into my house last night," Burke's voice said. "They came to kill me, but I was too clever for them. I sleep in my den now, and I have extra locks on all the doors so they can't get to me."

The sounds in the outer office had ceased.

Judd's voice again. "Did you report the break-in to the police?"

"Of course not! The police are in it with them. They have orders to shoot me. But they wouldn't dare do it while there are other people around, so I stay in crowds."

"I'm glad you gave me this information."

"What are you going to do with it?"

"I'm listening very carefully to everything you say," said Judd's voice. "I've got it all down" - at that moment a warning screamed in Judd's brain; the next words were - "on tape."

He made a dive for the switch and pressed it. " - in my mind," Judd said loudly. "And we'll work out the best way to handle it." He stopped. He could not play the tape again because he had no way of telling where to pick it up. His only hope was that the men outside were convinced that Judd had a patient in the office with him. Even if they believed that, would it stop them?

"Cases like this," Judd said, raising his voice, "are really more common than you'd believe, Harrison." He gave an impatient exclamation. "I wish they'd get these lights back on. I know your chauffeur's waiting out in front for you. He'll probably wonder what's wrong and come up."

Judd stopped and listened. He could hear whispering from the other side of the door. What were they deciding? From the distant street below, he suddenly heard the insistent wail of an approaching siren. The whispering stopped. He listened for the sound of the outer door closing, but he could hear nothing. Were they still out there, waiting? The scream of the siren grew louder. It stopped in front of the building.

And suddenly all the lights went on.