They had peered into the cavern and were waiting when they heard the explosion. They gazed at each other questioningly and with apprehension.

"What do you think it is?" asked Eva, questioningly.

Zita could, of course, offer no explanation and did not try.

Impulsively both girls took a very foolish chance. Both had thought of Locke and they started to run into the cave entrance and toward the sound of the explosion.

Zita was in the lead, and it was at this moment that the panic-stricken emissaries came tumbling and fighting their way from the den. Zita shrieked to Eva to save herself, and Eva, although unwilling to leave her, knew that now she could do nothing to save Zita, and took her only chance of escape.

As for Zita, the emissaries were too frightened to pay any attention to her. But behind them came the iron monster, without nerves, it seemed.

The Automaton saw her and pinned her to the rock wall until she was unconscious. Then, picking her up as though she were a feather, it carried her out to the beach.

Locke, the moment he freed himself from the hole which had so nearly been his grave, ran staggering toward the beach, for he felt instinctively that Eva and Zita were in danger.

Eva and Locke must have started at about the same time, she in her flight away from the Automaton, and Locke to find the den exit, for they met on the cliffside.

"Thank God you are safe!" exclaimed Eva.

Locke impulsively threw his arms about her and kissed her as they related their narrow escapes.

Locke resolved to follow the trail of the Automaton and to rescue Zita.

Also he had hopes of rescuing Eva's father at the same time. Eva wished to accompany him, but he would not think of it, and insisted that she return to Brent Rock and keep all the doors barricaded. In fact, he followed her almost to the house and saw that she entered safely, then hurried back to the beach.

With the aid of Eva's electric torch, which she had given him, it was no difficult task to trace the huge footsteps of the Automaton, though, one by one, the footprints of the emissaries took divergent directions, probably for the very purpose of confusing just such a pursuit.

He followed the main track, however, until he came to the banks of a small stream, and there the trail was completely lost, for the monster had stepped into the water. Locke waded to the other bank and hunted for further tracks, but there were none to be found. The Automaton had undoubtedly waded up-stream to the point where he had decided to dispose of Zita.

Nothing daunted, Locke started wading upstream. This stream ran in a gully between the rocks and the cliffs on either side, which were very high. Time and time again Locke thought of turning back for more searchers. But he hated to return to Eva without at least some news, and therefore he persisted.

He was at last rewarded, for just as he was about to turn to the right where the stream made a bend, he thought he heard a low laugh. He stopped dead in his tracks. Again the sound of the broken laughter came to him.

Cautiously Locke moved slowly forward until he could see around the bend.

It was a strange sight that met his gaze. Under an enormous overhanging rock he saw about fifteen men standing, while against the cliff he could distinguish the form of a girl. It was undoubtedly Zita. Sitting on a rock and quite close to her was Peter Brent.

The emissaries were clustered around the central figure, which was waving its arms of steel and indicating what they should do. As the Automaton gesticulated, tiny points of fire gleamed from its eyes.

Seen in the light of the lanterns held by the emissaries, the Automaton never looked more terrifying. Even Locke himself, who had encountered the monster so often, felt a cold chill as he watched him and his men.

Locke turned noiselessly, for well he knew that alone he could do nothing. He started to retrace his steps to Brent Rock, and no sooner had he arrived there than he told Eva that her father still lived and was uninjured, and that Zita was safe in the new den of the Automaton which he had discovered. Then he telephoned to his chief to send officers immediately to Brent Rock.

After the explosion that had killed Balcom and had come so near to killing Locke, when he had finally rescued himself and had drawn himself out of the hole, there was one who watched him.

It was none other than that mysterious being, Doctor Q. What twist of that disordered brain had brought him to the spot was not at once evident. However, as soon as Locke had left to go toward Eva, Doctor Q came from his hiding-place, madly smiling and wagging his head. He peered into the hole and, seeing nothing, lighted a match and thrust it far down into the darkness.

There was a sharp intake of his breath, for the match revealed to him the dead face of Herbert Balcom.

Doctor Q drew back and stood erect.

"Dead!" he muttered, as he ran his fingers through his hair dazedly.

"Dead!"

A strange thing happened. The mad light fled from the eyes of Doctor Q and the twisted brain seemed to become clear.

Suddenly in the very field the old man knelt down and prayed a thankful prayer for his recovery.

What was the strange power which Balcom had wielded over him, which death had snapped?

The officers arrived at Brent Rock and Locke was ready. The party left immediately to go to the rescue of Brent and Zita, and it took them only a short time to reach the spot which Locke had located.

Disposing some of his force below the hanging rock, Locke and some others went farther upstream. The two parties looked at their watches, waiting a certain time agreed on.

Then the two parties moved toward each other. As they came in sight of the spot, Locke experienced a keen disappointment. He could see no one.

Advancing farther, he discovered Brent still on the same rock. Guarding him were three emissaries. That was all. Zita, the Automaton, and the other emissaries were gone.

The three emissaries, seeing the numbers opposed to them, did not even offer to resist. They were placed under arrest, but nothing could induce them to tell where the others had gone.

To fail Zita after she had so nobly saved his life in the lair of the hypnotist was an unwelcome thought to Locke, and he resolved to rescue her at any risk. But first he felt he must restore Brent to his daughter, and therefore the party returned to Brent Rock.

Eva was beside herself with joy at the safe return of her father, and led him tenderly to his room and sent immediately for the doctor in order that he might not suffer from his exposure.

While this was going on at Brent Rock, Paul Balcom was rifling his father's papers in the apartment where Balcom had lived. He had unceremoniously thrown letters and documents all over the floor in his mad search for something. Finally he found what he was looking for, and, smiling triumphantly as he read the paper, he thrust it into his pocket and hurriedly left the place, not stopping even to pick up the papers scattered all about.

Zita had evidently been watching the house, for no sooner had he left than she ran up the front steps of the Balcom apartment.

In some way she had procured a key and let herself in. Then began a feverish search very similar to that which Paul had instituted. Only, this time Zita picked up all the papers, arranging them and placing them back in the drawers, after scanning their contents.

She had almost finished when a small book lying in a distant corner of the room caught her eye.

At a glance she saw that it was a diary. Turning the pages rapidly, she finally came to one over which she fairly gloated, for its information, sold to the proper parties, might make her independent for life.

Even as she was gloating over her find there came the sound of many feet in the front hallway. Zita had no time to run out of the room before the door opened, giving entrance to six emissaries, surrounding her.

The emissaries locked all the doors and tramped out. Only their leader remained for a moment to throw a parting shot.

"Remember," he threatened, "this house is watched. See that you act accordingly. You will, if you know what's good for you."

Then he slammed the door and locked it behind him.

For a long time Zita sat there, too despairing to move. Then her ear caught the sound of stealthy footsteps in the hall, and she ran and hid behind the portieres. The door opened slowly and Paul stole again into the room.

Having nothing to fear from him, Zita came from her hiding-place and confronted him. Paul was startled for a moment at her sudden appearance, but recovered himself on seeing that it was Zita.

The paper that he had stolen from his father's desk had proved to him that Zita had become highly desirable, and he was not one to miss such an opportunity.

As he questioned her, Zita told him briefly her story, or, rather, such portions of it as she thought it desirable for him to know. Paul, in turn, assured her of his undying friendship and something more. His earnestness almost made it seem true, and he talked in his most fascinating and attractive manner. He finally ended his conversation with a direct proposal of marriage. But he had overstepped the mark and Zita was not to be fooled.

"Paul"--she laughed scornfully now--"you should be on the stage. It needed only this proposal to prove to me that I am really Peter Brent's daughter."