The slender man, who clearly was the leader, crossed the room.

"Seeing ghosts, George?" he asked. "Or maybe you're anxious for a glimpse of what Simmons hasn't got any more. Why not show him the big event, Simmons?"

His laugh, scarcely audible, was like the wrath of a gigantic sneer.

Garth's hand crept to his pocket and closed over his revolver. George drew back.

"Look yourself, Slim, and it ought to be done."

The other swung on him angrily.

"Do you think I'm bringing him here without checking him up. He doesn't have to take his mask off to show you a scar. The lot of you look like sudden wealth for a nerve specialist. Sit down. We'll get to business."

He swung on Simmons.

"I know how you feel about that. Now, listen. All you know is that we wanted a scientific fellow who doesn't use his profession exclusively for the benefit of humanity. Also one without any nerves. I've always heard that of you."

Garth nodded, smiling a little to himself. Lack of nerves had been the inspector's chief requisite. Now the criminals demanded the same quality. He stood, as it were, between two deadly fires. He wondered if murder was on the boards. He recalled the slip of white paper in his pocket, questioning if he would be able to finger it, to scratch upon it those vital invisible directions before these sharp and overcurious eyes.

The slender man hurried on, glancing at his watch.

"We're waiting for one more. At first all you have to do is to keep close to George. We're going to crack a safe."

His voice colored apologetically.

"No jewelry or bags of gold. George falls for that cheap stuff now and then, but you needn't be ashamed of this job, Simmons. By the way, I don't have to ask you if you duck your lid every time the band blats 'Oh, say, can you see!'"

Garth shook his head.

"Say, Simmons," George broke in, "you talk yourself to death. That explosion must have hurt your voice something fierce."

Again Garth tried to approximate the croaking tone he had heard at the bridge.

"Talk's as cheap and easy as cracking safes."

He risked it for its effect on the others. Moreover it was an antidote for his nervous strain to give that much rein to the antagonism he already experienced for the huge, dark fellow.

Secretive laughter greeted his daring. A gesture from the leader halted George's movement, almost instinctive, to resent the affront physically.

Then three faint and regular splashes came from the water.

They all held their poses of the moment statuesquely until, at a nod from the leader, the intellectual-looking youth arose and moved towards the door.

During that moment of waiting Garth tried to fashion what he knew into a recognizable pattern, but the pieces were incomplete. He could only wonder why they had sent to Chicago for an anarchistic chemist to connive with this expert at a task as simple as cracking a safe.

The youth turned the lock and opened the door a little. It was pushed boisterously against him, and, beyond his amazed back, Garth had a glimpse of a gaudily colored skirt. The others had risen. The leader, grasping the youth's elbow, shoved him to one side, and Garth, his view un.o.bstructed now, gazed incredulously at Nora's blazing, painted face.

His first impulse was to cry out and warn the girl back from this ambush into which she had unaccountably strayed. He gripped the edge of the table. He half arose. For a moment the room went black. All at once he realized that her presence at this unique rendezvous must be without the slightest ambiguity. Perhaps it was an ill-advised attempt to rescue him from the net. He waited tensely for some word. His heart sank. She couldn't recognize him behind the mask.

He wouldn't lie to himself any longer. Nora, whom he had always seen in black, wore a flashy dress. She had given the conspirators their own signal. She received from them a welcome of anxiety.

The room darkened again. He sat in a frozen silence. He saw and heard as from a vast distance.

"Whole force at your heels, Nora?" the leader asked gently.

Closing the door, she faced them breathlessly. Her eyes flashed, but fear lurked there, too.

"No," she said, "but it might be tramping on the dock without your guessing it. Listen, Slim."

She raised her clenched fists.

"There's a bull here. There's a cop with his hand at your throat."

"Nora! You're having a nightmare."

"Hold on," George said. "Nora ought to know."

"Yes," she gasped, "and it's straight."

Slim relaxed.

"From your father?"

She nodded.

"How in--"

"I don't know," she said, "but he was sure he'd have a stool with you to-night. He's tried so long I know he wasn't bragging. Slim! We can't trip up now. I've worked too hard. You've told me what a mess you made last time, when that cop, Kridel, was croaked. Where will we be if anything like that's pulled again?"

"Easy, Nora," Slim said. "Maybe we wouldn't be any worse off than we were then. Has anybody burned in the chair for that? Does anybody know who croaked Kridel? Well--the man who did it. Don't lose your nerve. The cops would have a fine time getting a witness in a murder case out of this crowd. And, if what you say is so, maybe the same thing will happen to-night, only in a more convenient spot."

"What are you going to do, Slim?" she asked. "Tie him up, but no more murder. I quit at that."

"Leave it to me," he muttered. "Show me the bull."

Garth received the words as a condemned man probably hears the voice of a judge who wears the black cap.

The girl glanced rapidly around. Then, advancing steadily to the table, she raised her hand and pointed at Garth.

He stared fascinated at the finger which, a few hours ago, he had held violently in the rush of his pa.s.sion. He was aware of the flashing eyes which that afternoon had been wet with tears. But his brain was dull. He waited patiently for the exposure which now appeared unavoidable because of the woman he loved.

She spoke evenly.

"Who could it be but this man that hides his face? There's no doubt about the rest of you. You only have to see, Slim, whether this fellow, Simmons, has got a face."

"He had the word," the leader answered, "and look at that scar. But you're right, Nora. If there's a bull here he's behind that mask."

"Then make him take it off," she said.

Garth raised his hands. His croaking voice was torn with dismay.