Zita nodded an eager acquiescence and left him, returning to the house.

That evening Locke, returning from a stroll around the grounds, noticed a movement in some shrubbery at the side of the foot-path. He went closer to investigate, and a rough-looking individual broke from cover and ran away through the underbrush as fast as he could go. It was too dark to follow and Locke hastened his steps to the house, fearing some new deviltry on the part of the Automaton or his emissaries.

He had just entered the darkened hallway when, much to his surprise, he saw the figure of a man, leaning heavily on the arm of a woman, descending the stairs.

He stepped behind some portieres and waited until they reached the foot of the stairway. Then he stepped out and confronted them.

Zita gave a startled cry, and would have fled had not Locke caught and held her. As for poor Brent, he simply stood there, swaying from side to side and smiling foolishly.

Eva heard the commotion and came running down the stairs. She was amazed until Locke explained the situation to her. Then her indignation knew no bounds. Putting her arms around her father, she turned to Zita.

"How dare you?" she demanded, scathingly. "For doing this you will leave this house immediately and--never return."

Zita, for a moment, was on the verge of breaking down, but recovered herself and, with an angry retort on her lips, went out, slamming the door behind her.

Zita slipped around the house and to the hedge designated by Balcom as their meeting-place.

She was surprised but relieved when she did not find him there, and glanced at her wrist watch, which stood at a few minutes past eight. She was about to turn around when she caught sight of a bit of paper. Taking it, she read:

Bring him to my rooms.

That was all, and the message was unsigned.

Zita greatly feared Balcom's wrath at her failure, but, nevertheless, she started for his apartment.

At that moment Balcom and the mysterious Doctor Q were talking in the latter's dingy laboratory. Doctor Q's mind, for the time being, at least, seemed perfectly clear, and he had formulated a daring plan.

"Send Locke word that you will give yourself up," he was saying, "but tell him that he must come to your apartment to get you. I will do the rest."

Balcom left hurriedly and was driven directly home, where he got Locke on the telephone and repeated the instructions that Doctor Q had suggested.

"Am I to understand that you intend to turn state's evidence?"

questioned Locke, doubtfully.

"Assuredly," hastened Balcom.

"Then I'll be right over."

As Balcom hung up the receiver he chuckled sardonically. He was just turning to an antique brazier to arrange for Locke's reception when Zita was announced and at once admitted.

"I've failed, Mr. Balcom," she apologized, "failed miserably. Locke took Mr. Brent away from me--and they ordered me never to return to the house."

"You little idiot!" Balcom almost hissed. "I'll not tolerate a failure, either. Get out!"

Although Zita almost went on her knees in her pleading to him, Balcom was adamant, and finally she left in utter despair.

Outside, she telephoned to Paul to see if she might induce him to use his influence in reinstating her in his father's good graces.

As soon as Zita was gone Balcom busied himself with the ancient brazier and was standing before a small image of Buddha. He took a small package and from it poured a powder into the bowl of the brazier. Then, going to the table, he wrote a short note, after which he went to a divan and awaited Locke's coming.

Balcom had not long to wait. A ring came at the door and Balcom leaped to his feet and lighted the powder in the brazier. Then he adjusted a gas-mask that Doctor Q had given him, and, returning to the divan, lay down, pulling a camel's-hair coverlet well over himself as he awaited results.

There was a rap at the door and a peremptory demand for entrance--a pause--and a whispered consultation outside.

"Open the door!" cried Locke, again.

As there was no answer, heavy blows were rained upon the door, and finally it gave way.

Three men stumbled into the room. They stared about, then started to search the place. One by one they started to cough. Locke, who was the farthest away from the brazier, seemed to be the least affected.

Finally he spied the note on the table and snatched it up. By the dim light he read:

You will never live to capture me. The deadly gas is even now killing you.

Locke gasped. There was the sound of a heavy fall behind him. He turned and saw that one of his men was down.

He took a step forward, when the other pitched on his face.

Locke tried to rescue them, but by this time the deadly fumes had reached him and he, too, fell to the floor, coughing his life away.

At that moment Balcom got up from the divan and, stepping over Locke's prostrate body, left the place, forgetting to close the door behind him.

When Zita telephoned Paul, Paul made an immediate appointment for her to meet him at Doctor Q's, and when she arrived there Paul was already in conference with the doctor.

Over the telephone Zita had already given Paul a brief account of what had happened, and thus the two men were prepared with a plan when she arrived.

"Get Eva to the hypnotist's on River Street," instructed Doctor Q. "Tell her that I have been hypnotized and that under the spell I will tell all."

It was a desperate thing for Zita to attempt, after treating the Brents so shamelessly. But there was no alternative. For she knew well that, with Balcom, only a success would offset her miserable failure earlier in the evening. Besides, were not her fortunes tied up with Balcom--or perhaps with Paul? She did not demur, but left immediately for Brent Rock to make the attempt, revolving in her mind how she was to do it.

Zita had difficulty in persuading Eva to see her at all, but, once she had succeeded, the possibility that all the mystery might be cleared up appealed strongly to Eva. For Zita had framed her story cleverly and was playing desperately.

"Then I'll meet you at the hypnotist's in about half an hour," agreed Eva, after Zita had told her how friendless she herself was and how both Balcom and Paul had refused her aid.

Zita left Brent Rock alone and was passing a dark corner when a hand reached out and grasped her by the arm and she heard a voice that she recognized.

"Your failure has made me redouble my efforts," it hissed. "I have just killed Locke in my apartment and I--"

It was Balcom. But Zita waited to hear no more. Secretly she had always loved Locke. Though she had worked against him, the very thought that he might be dead shocked her. She tore herself from the grasp of Balcom before she could hear more and ran like a deer toward the apartment.

Fortunately, it was not far. She tore up-stairs and through the door that Balcom had left open.

Everything was as Balcom had left it, except that now the three men lay quite still. Zita staggered over to a window and threw it open.

Next she got water and extinguished the still smoldering powder. Then, falling on her knees, she tried to help the stricken men.

Not much time did she spend with the others, but to Locke with great tenderness she gave most of her attention. Tenderly she bathed his brow and frantically tried even to breathe her breath into his burning lungs.