Only Locke understood, and as he watched Zita he resolved to do all he could for her, realizing that some one else had made her a victim of her love and jealousy.

All breathed a sigh of relief when at last they came again in sight of the lights of Brent Rock.

There was just the trace of a shadow to cloud the momentary happiness at their safe arrival, as, on the steps, Zita refused to enter.

"I--I must say good-by," she murmured, wistfully, turning to go out into the night alone.

Nothing that either Locke or Eva could say seemed to swerve her purpose.

"Can't you see?" she exclaimed, finally, turning to Locke. "Balcom, Paul, and Doctor Q all trust me now. I can help you solve the mystery better if I leave the house."

This was so evident that Locke and Eva were forced to consent. They took her back to the city, leaving her where she could be unobserved, then returned in a very hopeful mood again to Brent Rock.

"I think she can and will help us," declared Eva, intuitively.

"Yes," agreed Locke, slowly, "and if Zita finds the record of her birth I believe we shall solve the mystery."

Worn out with the terrors through which she had passed, Eva bade Locke an affectionate good-night and went to her room, while he went to the laboratory and tried again to find an antidote for the Madagascar madness, a work that kept him up late and to which he returned again early the following morning.

It was on that following day, in the River Road apartment of De Luxe Dora, that Paul and she were having a demi-monde lovers' quarrel. Paul was intoxicated, and Dora may have been angry about that. Or it may have been that she was jealous of some other woman. However, they were quarreling fiercely when there came a knock at the door.

"You open it," flashed Dora to Paul.

He demurred a moment, then, changing his mind, consented and crossed to the door, while Dora ran to her own room and hid.

Paul was very much surprised to find that the visitor was Zita, much excited.

"I want you to help me on something of great importance," she exclaimed, almost before she had entered.

"Why, certainly! Anything you desire!" hiccoughed Paul. "Come on in."

Zita entered the apartment and they crossed over to the chaise-longue, where Zita made her direct plea.

"Help me find the record of my birth," she begged.

Paul pulled his wandering wits together and thought a moment; then a particularly crafty look came into his eyes as he detached a key from his key-ring.

"Here, take this," he directed. "It's the key to my father's apartment.

The records you want are there. He and I have quarreled and you can go as far as you like."

Zita took the key eagerly, thanked Paul profusely, and started for the door.

She had barely passed the threshold before Dora, who had heard all, was at the telephone in her own room and was angrily calling up Balcom at his apartment.

Balcom, assisted by his Madagascan servant, was at the moment packing a trunk, perhaps preparatory to a hasty flight, should that become necessary. The moment the telephone rang he picked up the receiver and nearly choked with anger as he heard Dora's whispered voice over the wire.

"Paul has given Zita the key to your apartment," Dora hastened, "and she is coming over to steal the record of her birth."

"She is--eh? Well, I'll take care of that," growled Balcom, as he rang off.

Balcom went to a drawer in the table and from it took a large book.

Rapidly he turned over the pages until he found what he wanted. Then he made an erasure and an entry and replaced the book in the drawer. Next he called the servant.

"When she comes, you make her a prisoner," he directed. "Understand?"

The Madagascan nodded and raised one of Balcom's hands to his own forehead as a sign of his fidelity.

Balcom went out and the servant stepped into the empty trunk to await the arrival of Zita.

But it was a very different person with whom the Madagascan had to contend in the end.

On leaving Dora's apartment, Zita telephoned Brent Rock, and Locke answered immediately. Locke readily agreed to make the search of Balcom's apartment in Zita's stead.

When the Madagascan heard a key in the door he stealthily peeped from his hiding-place and saw, instead of Zita, Locke.

Locke's back was turned, and the Madagascan, undaunted, sprang from the trunk and leaped, catlike, on Locke's back. But he had not reckoned on his antagonist. Locke, always on guard, was not taken quite by surprise.

He caught the savage in a jiu-jitsu hold, throwing him over his head to land in a far corner of the room.

In spite of the fall, the Madagascan bounded to his feet, like a rubber ball, but a few stiff jabs from Locke soon took all the fight out of him and he lay still, completely knocked out.

Locke made a hurried but systematic search of the room, and finally found the book that he sought, taking it and returning to Eva at Brent Rock.

After telephoning, Zita went directly to Doctor Q's laboratory, to which she was admitted after he had seen her through his periscope annunciator.

The doctor was fumbling with a test-tube, from which some heavy fumes were issuing. He motioned her to a chair, near a table upon which were many papers which looked to Zita as though they might be of importance.

Always quick to act, Zita raised her hand as if to arrange her hair, and as she did so she purposely knocked the test-tube out of the doctor's hand. The acid spattered on some of the papers, quickly setting them afire.

Doctor Q, wildly excited, started to beat out the flames, and in so doing allowed several unseared letters to flutter to the floor. One in particular arrested Zita's attention. It was a drawing, a plan of some sort, and was marked, "Plan of Den."

Zita placed her foot on it, and, while Doctor Q was engaged with the small blaze, she reached down and, hastily folding it, thrust it into one of the low shoes she was wearing. Then she went to Doctor Q's assistance and in a jiffy the fire was out. The doctor was furiously angry at her, and, feeling that she had accomplished all that she might expect, she expressed her regrets for the accident and went out before his anger became any worse.

Thus it was that Zita arrived at Brent Rock only a few moments after Locke, whom she found in the library with Eva, turning over the pages of the record he had secured at Balcom's.

The record purported to be a record of marriages of Wallace County, New York, and Locke finally found an entry that read, "Peter Brent and Rita Dane."

For a moment Zita was stunned. It was her mother's name.

Locke smiled. "Yes, Zita," he said, quietly, "for a moment Eva and I were surprised, too. But it's a palpable forgery. Balcom has tried to prove that you and Eva are half-sisters, but look."

He handed her a powerful magnifying-glass and through it the clumsy forgery stood out in all its crudeness, showing plainly where other names had been erased and these inserted.

Zita was greatly disappointed, for she had thought that at last she would establish her identity. Then she remembered the paper she had hidden in her shoe. She slipped the paper out and handed it to Locke, who was greatly excited over its importance.

They were still studying it when Locke heard a strange noise, as of shuffling feet, in the hallway. He jumped to the door, and there, in the dim light of the stairway leading down to the Graveyard of Genius, he saw a knot of men carrying another man, who was evidently helpless.

Locke started forward, but they were gone.

Eva hurried up-stairs to her father's room, fearing something was wrong.