There was no doubt of it. She was the girl in the night club, the dancing girl with the flowing black hair and the mask-like smile, who had led him to Conroe and then brought the spotlight to his face to spring the trap too soon. Frantically Jeff fought to control his excitement. He knew his face was white and he avoided the doctor's puzzled glance. But he couldn't control the angry fire burning in his mind, the little voice screaming out: "He's here; he's here, somewhere!"

But why was she here? The doctor had called her "Blackie." He had spoken to her with familiarity. Jeff's mind whirled. He had the strangest feeling that he had missed something somewhere along the line, that he knew the answer but couldn't quite grasp it. What could the girl's sudden appearance in the Center involve?

Or had her appearance at the night club been the unusual one?

A buzzer rang and the office door opened to admit a small, weasel-faced man. The doctor looked up and smiled. "Hello, Jacques. This is Jeff Meyer, the new recruit. Take him down and get him quartered in, all right? And you might brief him a little. He's awfully green."

The little man scratched his long nose and regarded Jeff with a nasty smile. "A new one, huh? Where are you going to line him up?"

"No telling. We'll see where the tests put him, first. Then we'll talk about jobs."

The smile widened on the little man's face, turning down the end of his long pointed nose and revealing a dirty yellow row of teeth. His eyes ran over Jeff from head to toe. "Big one too. But then, they fall just as hard as the rest. Want me to take him right down?"

Schiml nodded. "Maybe he can still get lunch." His eyes shifted to Jeff. "This is the Nasty Frenchman," he said, motioning toward the little man with his thumb. "He's been around for a long time; he can show you the ropes. And don't let him bother you too much—his sense of humor, I mean. Like I say, he's been around here a long time. You'll get quarters and you'll be expected to stay with your group for meals and everything else. That means no contacts outside the hospital as long as you're here. You'll get the daily news reports, and there are magazines and books in the library. If you've got other business outside, you haven't any business in here. Any time you leave the Center it's considered an automatic breach of contract."

He paused for a long moment and gave Jeff a strange look, almost a half smile. "And you'll find that questions aren't appreciated around here, Jeff. Any kind of questions. The men don't like people too much when they ask questions."

The Nasty Frenchman shuffled his feet nervously, and Jeff started out the door. Then the little man turned back to Dr. Schiml. "They brought Tinker back from the table about ten minutes ago. He's in pretty bad shape. Maybe you should look at him?"

"This was the big job today, wasn't it?" Schiml's eyes were sharp. "What did Dr. Bartel say?"

"He said no dice. It was a bust."

"I see. Well, it may be just the diodrax wearing off now, but I'll be down to see."

The Nasty Frenchman grunted and turned back to Jeff. His face still wore the nasty little grin. "Let's go, big boy," he said, and started down the hall.

Jeff watched the corridors as they passed, counting them one by one, trying desperately to keep himself oriented. He glanced at his watch and angrily sucked in his breath. Minutes were slipping by, precious minutes, minutes that could mean success or failure. A thousand questions crowded his mind, and behind them all was the girl. She was the key, he was sure of it. She would know where Conroe was, where he could be found....

They reached an elevator, stepped aboard and shot down at such dizzying speed that Jeff nearly choked. Then, suddenly, they came to a jolting stop and stepped into a dingy, gray corridor that was dimly lit by bare bulbs in the ceiling.

The Nasty Frenchman punched a button in the wall and turned to regard Jeff. The sneering little smile was still on his lips as the far-off rumble of a jitney grew to a sharp clatter. A little car dropped down from its ceiling track. The little man hopped in nimbly and motioned Jeff in beside him. Then the car took off for the ceiling again, swinging crazily and speeding down the maze of corridors and curves.

Jeff stirred uneasily, growing more and more confused with every turn. "Look," he broke out finally, "where's this thing taking us?"

The Nasty Frenchman turned pale eyes toward him. "You worried or something?"

"Well, it looks like we're headed for the center of the Earth. I'd like to be able to find my way out sometime—"

"Why?"

The question was so blunt that it left Jeff's jaw sagging for a moment. "Well, I'm not planning to spend the rest of my life in here."

The Nasty Frenchman guffawed. It was not a pleasant laugh. "Here for a nice restful vacation, huh? You wise guys are all the same. Go ahead, dream—I won't bother you."

The little man turned his attention to the controls and the car swung sharply to the right and headed down another corridor. Jeff scowled as he watched the lighted corridors flash by. Were they speeding so far, so deep in the depths of the building? Or was this part of a definite plan to confuse, to lose recruits in the mammoth place so completely that they could never find their way out? Jeff shrugged, finally. It really didn't matter too much. He had one job and only one. He could worry about escape when it had been accomplished.

"That girl," he said finally. "The doctor called her 'Blackie.' Is she down here where we're going?"

"How should I know? I don't keep her on a leash." The little man's face darkened and his eyes turned suspiciously to Jeff.

"I mean, is she one of the group—one of the Mercy Men?"

The Nasty Frenchman threw a switch sharply, swerving the speeding car through a long, dim passage. He ignored the question, as if he hadn't heard it. In the dim light his skin was pasty yellow and wrinkled like a mummy. The cruelty and avarice on his face was frightening.

Jeff watched him for a moment or two, then said, "What brought you here? To the Mercy Men, I mean?"

The Nasty Frenchman's eyes flashed poisonously, his face a horrid mask. "Did I ask you your racket before you came in?"

"No."

"Then don't ask me mine. And you won't forget that, if you're smart." He turned his attention sharply to the controls, ignoring Jeff for several moments. Finally he said, "You'll share a room and you'll eat at eight, noon and six. Tests should start tomorrow morning at eight-thirty. You'll be in your room when the doctors come for you. You won't have any status here until you're tested. Then you'll sign a release and wait for a job assignment. You won't have any choice of work; that's just for the older ones. Some of the work is with central nervous system, some is with sympathetic; some work concentrates on spinal cord and peripherals, but most of the interest these days is in cortical lesions and repair. That pays the best, too—couple hundred thousand at a crack, with a fairly good risk."

"And what's a fairly good risk in here?"

The grin reappeared on the little man's face again. It was almost savage in its cruelty. "Ten per cent full recovery is a good risk. That means complete recovery from the work, no secondary infection, complete recovery of faculties—in other words complete success in the work. Then a fairly good risk runs slightly lower—more casualty, maybe five per cent recovery. And a high-risk job averages two per cent—"

The grin broadened. "You've got a better chance of living sitting under an atom bomb, my friend. And once you sign a release, relieving the hospital and the doctors of all responsibility, you're in, and held to your contract by law. This is no vacation, but if you're lucky enough to come through—" The little man's eyes were bright with eagerness. "They pay off—oh, how they pay off. If you're lucky, you'll get a good starter, maybe a hundred thousand, with good risk." He scratched his nose and regarded Jeff closely. "Of course, there are incomplete recoveries, too. They have trouble keeping them out of the news, if they ever leave. Pretty messy, sometimes, too."

Jeff felt his face paling at the cruel eagerness in the little man's voice. What could bring a man to a place like this—especially this kind of a man? Or had he been a different kind of a man before he came in? How long had he been here, waiting from experiment to experiment, waiting to live or to die, waiting for the payoff, the Big Cash that waited at the end of a job? What could such an existence do to a man? What could there be to drive him on? Jeff shuddered, then gasped as the car gave a sudden lurch around a corner and settled to the floor.

The Nasty Frenchman hopped out, motioned to Jeff to follow. They started walking toward the escalator at the end of the passageway. Jeff searched each doorway they passed, keeping alert for a sign of the black-haired woman. "Look," he said finally. "This girl—Blackie, I mean—who is she?"

The Nasty Frenchman stopped in his tracks, glared at Jeff. "What is she, an old family friend or something? You keep asking about her."

"I know her from somewhere."

"So why bother me with your questions?"

Jeff's face darkened angrily. "I want to see her, all right? Don't get so jumpy—"

The little man whirled on him like a cat. Jeff's arm was wrenched behind his back until he felt the tendons rip. With unbelievable strength the Nasty Frenchman twisted the huge man back against the wall and glared up at him with blazing eyes. "You're a smart guy, coming around here, asking questions," he snarled, giving Jeff's arm a vicious wrench. "You think you can fool me? You ask about this, you ask about that—why so nosey? Blackie ... me ... everything. What are you doing here? Going after the Big Cash or asking questions?"

"The Cash!" Jeff gasped. He twisted to wriggle free of the iron-like grip.

"Then don't ask questions! We don't like nosey people here; we like people that roll dice square and mind their own business." The little man gave the arm a final agonizing wrench and released it. He jumped back, poised, eyes savagely eager.

Every instinct screamed at Jeff to rush him, but he slumped against the wall. Rubbing his aching arm, he fought for control. He knew a fight now could ruin things completely. Already he had blundered terribly. He cursed under his breath. How stupid he'd been not to have realized how unpopular questions would be to people in a place like this. And surely the word would get to the girl now that he was asking about her. Unless he could get to her first—

Still rubbing his elbows painfully, he turned to the Nasty Frenchman. "Okay, let it go," he growled. "Where do we go from here?"

The room was small and barren. Dingy and gray, it matched Jeff's spirit perfectly. He entered it with the Nasty Frenchman at his heels and stared at the two stark hospital beds against the far wall, the two foot lockers, the two small desk-and-chair combinations. There was no window in the room. Indeed, there was nothing about the room or corridor to prove that they were not twenty miles underground. Certainly the jitney ride had been no reassurance to the contrary.

The dim wall lights glowed on scrubbed, peeling paint, and the floor was covered with clean but well-worn plastic matting. Against one wall was a TV set. Between the beds a door led into a compact lavatory and shower. Glancing in, Jeff saw the lavatory was also connected with the adjoining room.

"It's no Grand Hotel," the Nasty Frenchman said sourly. "But it's clean and it's a bed. This corridor quarters your whole unit—the C unit. Other units are on other floors, up and down."

Jeff looked around the room gloomily. "Where can I eat?"

"The mess hall's four flights down. Take the escalator at the end of the hall. It closes in half an hour, so you'd better step on it. And if you're smart, you won't go wandering around. These boys in gray you see here and there don't like us very much." His face creased into a sardonic grin as he started for the door. "And you'd be smart to change before you come down. The faster people stop thinking you're new here, the happier you'll be." With that, he turned and disappeared down the hall.

Jeff gave a sigh, and prowled the room. One of the foot lockers held an amazing assortment of clean and dirty clothes. On the floor of it lay a large heap of dirty shirts and trousers, and nested squarely in the center of the pile was a heap of gold rings and wrist watches. Jeff blinked, not quite believing his eyes. He hadn't thought to ask about his room-mate, but apparently he had one who had not yet made his appearance.

Apparently everyone wore similar clothing. He found the other locker filled with clean shirts and dungarees. Swiftly he started to change, his mind racing. His body was sore all over and he felt a dry, hot feeling around his ears from lack of sleep. His arm ached miserably every time he moved it. If only he could sleep for a little while. But he knew there was no time to be wasted. In the mess hall there would still be people. Somewhere among them he would find the girl....

Carefully he considered the problem. The girl was the key. He had to find her, to make certain that Conroe was here. And he had to find her quickly, catch her unawares, before she had a chance to alibi or hide. Conroe would be hidden; he would never come into the open until he was sure that he had not been followed. He too must be taken unawares. Jeff had seen Conroe slip out of too many traps in the past. A blunder now could be the last. And if Conroe had time to plan, there would be many, many blunders.

A car buzzed down the hall as he stood in the room and stopped a little way from the door. There were voices, subdued, yet carrying a sharp note of frantic excitement. Jeff paused, listening to the combination of unfamiliar sounds: a grunt, a low curse, a rustle of whispered conversation, a low whistle. Then the door to the next room banged open and a rumble and squeak of wheels came to his ears.

"Jeez, what a job!"

"Yeah, looks bad. Did the doc see him?"

"He said he'd be down—"

"—gotta let it wear off before you can tell. This was the works, this time."

Jeff walked quietly to the door of the connecting lavatory, his nerves tingling. A new sound was apparent, an unearthly sound of labored, gurgling breathing. Jeff shivered. He had heard a sound like that only once before in his life: in a rocket during the Asian war, when a man had been struck in the throat with a chunk of shrapnel. Carefully, he pushed the door open an inch, peered through....

There were three men standing in the room, maneuvering a man—if it was a man—from the four-wheeled cart onto the bed. The man's head was covered to the shoulders with bandage. A patch of fresh blood showed near the temple, and a rubber tube emerged where the mouth should have been.

"Got him down? Better cover him closer. Restrainers—he may jump around. Doc said three weeks for shock to wear off, if he makes it through the night."

"Yeah—and this is the Big Cash for Tinker too. Harpo nearly beat him to the job, but Schiml had promised him—"

Jeff shuddered. This, then, was one of the Mercy Men, finished with a "job." The gurgling sound grew louder, measuring itself with the man's breathing—short, shallow, a measure of death. An experiment had been completed.

Jeff closed the door silently. His face in the mirror was pasty white and his hands were shaking. Here was the factor that had been plaguing him from the start, finally breaking through to the surface. The road he was traveling was a one-way road. He had to find Conroe and get off the road quickly, while he could. Because he dared not travel the road too far....

The air in the corridor seemed fresher as Jeff started for the escalator. It was almost two o'clock and he hurried, anxious to reach the mess hall before it closed. He consciously fought the picture of the man on the bed out of his mind. With effort he focused his attention once again on the girl. At the end of the corridor he stepped onto the creaky, down-going escalator.

If only he could check with Ted Bahr, make certain that the trail had really ended at the Hoffman Center, make sure that Conroe was not really somewhere outside, still hiding, still running. One thing seemed certain: if Conroe were really here, he too would be faced with the testing and classification; he too would be traveling the same grim road as Jeff himself. And as a newcomer, he too would be under suspicion and scrutiny.

Jeff stopped short on a landing. He was suddenly aware that he had lost count of the flights he had gone down. He looked back to check his bearings, then moved around to the stairs moving up. The escalator creaked and groaned, as if every turn would be its last, and Jeff stared dreamily at the moving wall, waiting—until he passed the open well to the opposite stairs.

He froze, his mind screaming. Unable to move, he stared at the pale, frightened face of the man on the down-going stairway. In the brief seconds while they passed, he stood rooted, paralyzed, unable to cry out. Then with a hoarse yell he turned. Half-stumbling, half-falling, he ran down the up-going stairs until he reached the opening.

Then he vaulted across the barrier, crashing his shoulder against the wall as he went through. He caught a glimpse of the tall, slender figure running from the bottom of the stairs into the corridor at the bottom, and he shouted again in a burst of blinding rage. He took the steps three at a time, his mind numb to the pain as his foot struck the solid floor and twisted, sending him sprawling on his face. In an instant he was on his feet again, running, frantically, blindly, to the end of the corridor.

It broke into two hallways, going off in a Y. Both were dark and both were empty. Jeff stood panting, almost screaming out in rage, his whole body trembling. He started blindly down one corridor, jerked open a door and stared in at the small, empty office. He tried another door and another. Then he turned and ran back to the Y, spun around the corner and ran pell-mell down the second corridor. Only his own desperate footfalls echoed back to him in the darkness.

Back at the Y, he sank to the floor. Still panting, he sobbed aloud in his rage, clenching his fists as he tried to regain control of his spinning mind. Rage there was—yes, and hatred and bitter frustration. But also, tumbling through his mind in a wild, elated cadence, was a cry of sheer, incoherent savage joy. Because he knew now, beyond any shadow of doubt, that Paul Conroe was among the Mercy Men.

He looked up suddenly at the two figures approaching him from the lighted corridor. One of them held a tiny, deadly scorcher pistol trained on his chest. The other, a huge, burly man, reached down and jerked Jeff's face up into the light. "What's your unit?" the harsh voice grated.

Jeff glimpsed the gray cloth of the man's jacket, the official-looking black belt over his shoulder. "C unit," he panted.

The blow caught him full on the chin, twisting his head around with a jolt. "Wise guy, wandering around without a pass," the voice growled. "You goddam scabs think you run the place, don't you?" Another blow struck him behind the ear, and a fist caught him hard in the pit of the stomach. As he doubled over retching, a smashing blow caught his chin, and he tasted blood in his mouth as his knees buckled under him.

He felt them, vaguely, half-carrying, half-dragging him down the corridor. He heard a door open and fell face down on the floor. A harsh voice said, "Here's your room-mate, scut. Keep him home from now on." And the door slammed behind him.

Painfully, he raised himself on his hands, shook his head dazedly.

"You look like you're sick or something." The voice from the bed was hard and insolent.

Painfully, Jeff jerked his head up and stared. The girl blinked coldly and pulled a frazzled cigarette from her blue cotton shirt. She flicked a match with her thumb and touched off the smoke. Then she stared down at Jeff mockingly. "Sorry, Jack," said the girl called Blackie. "But it looks like we're roomies. So you might as well get used to the idea."