"My--children," he murmured, "I see that it is not too late for me to find happiness, after all. Our enemy is dead. It was Balcom, of course, who was in that frame of armor, who used that terrible poison that stole away Brent's mind. The iron monster will walk no more. Henceforth Peter Brent and Miss Eva and you, Quentin--will--"

Doctor Q had not time to finish the sentence.

The door burst inward.

The Automaton, its eyes aflame, stalked in among them!

CHAPTER XXV

As the Automaton crashed its way into the room all sprang back terrified, aghast.

For this monster, they had felt sure, was now nothing but an inanimate shell of armor, since Balcom was dead.

Yet here it was, stalking toward them and evidently as bent on destruction as ever.

What did it mean?

In an instant Locke had helped Eva through an open window and turned to assist Zita. But Doctor Q forestalled him and had already taken her in his arms and had fled with her into another room.

For the moment Locke was surprised to see that the Automaton totally ignored him. Instead, it stalked to the door and wrenched it open.

There, cowering in the hall, in abject terror, was De Luxe Dora.

How and why she had come there was a mystery. But the Automaton did not hesitate. It raised its hands and, as it did so, long flashes of blue flame leaped from the steel finger-tips toward the unfortunate woman.

Once she shrieked, then crumpled and fell dead.

The monster then turned its attention to Locke, striding toward him with a menacing gesture. But the diversion due to Dora had given all just the time they needed to make good their flight. Locke threw a chair to impede the progress of the monster, and then, as he saw that all the others were safe, he lightly vaulted out of the window himself, to find them waiting for him in the little yard below.

"What do you make of it now--father?" asked Locke of Doctor Q. "Balcom is dead. Who is now in the iron man?"

Doctor Q shrugged. It was a mystery to him as much as ever, and he seemed unable to throw any light on it.

"But De Luxe Dora," queried Zita. "What had she come for? Why was she struck down--first?"

Again Doctor Q shook his head.

From the yard they could hear the Automaton's heavy tread in the room and, as there was nothing to be gained by remaining, they left the yard and hurried away out of the neighborhood.

They had not gone far, however, when Doctor Locke came to a full stop.

"I must go back," he exclaimed.

For a moment all thought he had again taken leave of his senses. Yet he was obdurate.

"Miss Brent--Eva," he explained, "you know that a grievous wrong has been done your father through me. He lies ill of that most terrible of diseases, the laughing madness. I alone possess the antidote, and it is in the laboratory that we have just left. I pray that that iron beast has not destroyed it."

At the mere words Locke turned as if to go back for it.

"No, Quentin," remonstrated his father. "You must remain to guard Eva."

"Then I will go," insisted Zita. "I am not afraid now. Even when the monster carried me off I overcame my fear, watched my chance, and escaped from his den, where he left me. I will go."

Finally Doctor Locke agreed that Zita might return with him, remain outside, and give the alarm if anything happened to him. Thus, after many remonstrances, it was agreed, and Eva and Quentin went on to Brent Rock.

No one had molested Brent in the mean time. The terror caused by the explosion, as well as the loss of Balcom, for the time, at least, had evidently cowed the emissary band.

While Eva made Brent comfortable, Locke went immediately to the laboratory, where he had something which he considered very important.

"Quentin," remarked Eva, as she joined him, "your father spoke the truth, I believe, when he said that it was Balcom in the Automaton, But if that was the case, who is in it now?"

Locke shook his head dubiously. "I give it up," he replied. "It's too deep for me. But whoever it is, he won't trouble us long, I'll wager.

I've been perfecting a special gun and an explosive-gas bullet. No one can shoot the monster. Nothing seems to stop it. But this weapon, I think, will at last prove a match for it."

Eva, who had always had the deepest interest in Quentin's work, listened attentively as he explained in detail the working of the new weapon.

"And now we come to the actual loading of these asphyxiating-poison bullets," concluded Quentin. "I really must ask you, Eva, to go into another room, for it is dangerous work and you must not risk your life here."

"But, Quentin," remonstrated Eva, "we've risked our lives so often together that I have ceased to be afraid of anything."

Quentin was insistent, and finally Eva agreed.

As Doctor Q and Zita neared the former's laboratory, they saw that all the lights in the house were out. Doctor Locke, against Zita's advice, insisted on going in, and told his daughter to wait outside. It was then that Zita disobeyed her father for the first time, for she flatly refused to be left behind.

"No," she insisted. "I found a father to-night and what we must risk we risk together. It is no worse than the peril from which I once escaped."

There was no reasoning with Zita, and they let themselves into the little yard and went up the back steps. When they came to the door of the laboratory they listened intently.

There was no sound. Then they mustered up courage and cautiously entered the room. For a long time they stood quite still, not daring to move.

Finally Doctor Q suddenly lighted a match.

The room was in terrible confusion, as though cyclone-swept.

Doctor Locke turned on an electric bulb and the room was flooded with light.

Everywhere there were traces of the Automaton. But the monster itself had left the place. Doctor Locke crossed to the other door. There was a sight that made them shudder. The body of De Luxe Dora was still huddled in a heap on the floor. She was quite dead.

But Doctor Locke had no time now to waste. Moments were precious. At any instant they might again be attacked. Feverishly he began to search for the bottle containing the antidote.

At last he found it, carefully hidden, and in a bottle fortunately not broken.

They left everything as it was and hurriedly left the place, on their way to Brent Rock.

Meanwhile, in one of the worst quarters of the city, down in the cellar of a huge warehouse, a mob of emissaries were gathered. They were discussing the things that had led up to the explosion in the Automaton's den, Balcom's death, and the arrest of their three pals.

Plans for the future they discussed, but, with their leader gone, these hardened men were still as helpless as children.

Suddenly above the din of voices a strange, familiar sound was heard, a sound as of clanking chains, and the blood froze in the veins of every man present. Then with wild shouts of terror they scattered in every direction, for the Automaton was stalking toward them.