Not only Eva, but the entire household was relieved by Locke's presence.

The cook rushed forward and, with a "God bless you, sir!" would have embraced him had he not stepped aside. Even the dignified old family butler tried to take his hand, an unheard-of liberty on his part. For, unknowingly, all had come suddenly to rely upon this quiet, unassuming young man.

Locke immediately asked to be shown to Flint's room in the hope that Flint might have left some clue behind. But, although they searched high and low, no success met their efforts.

It was then that they faced their darkest moment. Feeling, as they did, that they were encircled by hidden enemies, the very air they breathed became a menace. Every attempt to find the thread that might unravel the dark mystery proved futile. It was not to be wondered at that they despaired. Even the weird laughter of Eva's stricken father, echoing hollowly through the house, seemed to be mocking their efforts.

The Automaton's emissaries were anxious to do their job and return to the cave, for, like rats, they preferred the security best found underground. They did not lead Flint very far.

At the edge of the Brent estate there was an Italian marble fountain decorated with bronze dolphins and water-nymphs disporting themselves.

It was at this fountain that the men halted Flint and, with a final warning, left him.

For a few moments, such was his fear, Flint did not remove the bandage from his eyes, but moved groping around until his hand came in contact with the edge of the fountain. For a moment he stood quietly, listening for sounds of the emissaries. Then, as he heard nothing, he tore the bandage from his eyes, gazed wonderingly around him until his mind grasped his exact location, then, with a bound, started to run toward Brent Rock.

Had he noticed the bestial face of an emissary peering from the shrubbery he would have been even more frightened. Retribution, he would have known, would be swift and sure had he disregarded their commands and moved in another direction.

As Flint left the fountain Balcom, suave and well groomed as usual, was just giving his hat and stick to the butler when Locke and Eva, returning from Flint's room, encountered him in the hallway.

"Oh, Mr. Balcom," exclaimed Eva, "Mr. Locke and I are at a loss to account for Mr. Flint's disappearance! I told the gardeners, and they have hunted for him all over the estate and beyond, but he has disappeared as completely as though the ground had swallowed him."

Balcom expressed his utmost astonishment and at once insisted on going to Flint's room to solve the mystery himself.

Eva and Locke went directly into the library, where Locke for the first time had an opportunity to tell Eva the result of his visit to the chemist. The fact that they had discovered the nature of the toxin was in itself encouraging, and Eva felt that, even now, she could see the glimmer of a silver lining to the clouds.

"If we can only locate Mr. Flint, Quentin," she murmured, "I feel that much would be explained."

Hardly had the words passed her lips when, breathless and disheveled, Flint staggered up the stairs from under the porte-cochere and into the hallway. Balcom, just descending from his brief inspection of Flint's room, hailed him.

"What has happened?" he demanded. "Don't go into the library."

"I've just escaped from the Automaton," shouted Flint, "and I've found the antidote!"

Before Balcom could stop him he rushed into the library, Balcom following in a towering rage. Eva gave a startled little cry at the wild intrusion and Locke moved closer to her.

"Is the antidote that will restore your father's reason worth ten thousand dollars to you?" demanded Flint; then, before Eva could reply, added: "Speak quick! I've got to get out of the country to-night."

"Ten thousand!" gasped Eva. "Ten times ten thousand! Tell me what it is."

"Show me the money first," haggled Flint, "and remember I must have the hard cash."

"Just a moment, Eva," interrupted Locke. "Consider this thing well. We can deal with this fellow as a final resort."

Eva looked from Locke to Balcom, her mind in a turmoil, as the telephone-bell rang and Locke hurried to answer it.

In the room now there was a conflict of emotions and desires that fairly electrified the place. Eva ardently craved her father's recovery at all costs. Flint's avaricious mind wavered between a scheme nearing success and the possibility of failure and the fear of the Automaton. Balcom strained to hear the purport of the message that Locke was receiving.

At the sound of the chemist's voice Locke was tense with suppressed excitement.

"I've found the antidote," hastened to report the professor.

With a cordial word of thanks Locke turned from the telephone and faced the group in the room. As he made the announcement, Eva almost embraced him in the flood of relief at the thought of her father restored.

"Eva," growled Balcom, "you forget yourself. As Paul's father, I cannot countenance such actions."

"Mr. Balcom," interrupted Locke, "I am sure you will be kind in your criticism of Miss Brent. She has merely overrated my service to her."

"Paul shall hear of this," stormed Balcom.

"If your son cares to take the matter up with me," returned Locke, now on his dignity, "I am always to be found--here."

"Never mind," interposed Flint, who feared to see his chance slipping, "I've got to get out of the country. Mr. Locke, your antidote is probably valueless; mine is the certain one. Look at me, Miss Brent. Am I not cured?"

"You miserable sneak," scowled Locke, stepping over to him, "we don't need your assistance now."

"I'm dealing with Miss Brent," insisted Flint, insolently.

Eva, a bit nervous over Balcom's overbearing manner, interposed. "Mr.

Locke," she said, with just a touch of dignity for effect on Balcom, "this is a matter of life and death, and I am not in favor of permitting a proven antidote to be taken out of the country by this--this man. I have every confidence in you, but suppose--just suppose--that your chemist friend is mistaken."

Flint immediately saw his advantage and pressed it home. "Are you going to let ten thousand dollars stand in the way of your father's recovery?"

he insinuated. "Here," he added, taking pencil and paper from his pocket and writing hurriedly.

"Baker's dock," Eva read, as he handed her the paper, "until five o'clock."

Flint bowed decently enough to her, glanced upward, and, as he thought of Eva's father lying stricken with the Madagascar madness in the room above, an evil leer came over his fox-like face. As he left he completely ignored both Locke and Balcom, unless it was that the look in his eyes meant a sort of sinister triumph.

Locke followed him out of the library, and for a few moments Eva and Balcom were alone.

Balcom had been quick to realize that it would not further his plans if he continued to antagonize this high-spirited girl. He took another course. The kind and fatherly manner which he could assume so readily was now apparent.

"Eva, my dear child," he ingratiated, "I am really sorry for the hasty way in which I spoke, but, aside from our duty to International Patents, your marriage to my son has been my greatest hope and ambition."

"I can't see why you should wish a daughter-in-law of whose actions you disapprove," retorted Eva, pointedly.

It was a facer for Balcom and he quickly guided the conversation into less dangerous channels.

Eva's candid nature could not comprehend treachery of any kind in others, and yet, although she was unable to put a name to it, she had a vague feeling of insecurity in dealing with her father's partner. This feeling had been heightened by Balcom's actions. In speaking of the proposed marriage to Paul he had come quite close to her. She shuddered, for, out of the corner of her eye, only a few moments before, she remembered him in the same position when Flint had handed her the address, and she knew that Balcom had surreptitiously read it. Why had he taken that underhand method when, if he had only asked frankly to see the paper, she would have handed it to him without hesitation or suspicion.

Eva started to leave the library, but Balcom stopped her with a gesture.

"My dear," he said, "your father is stricken with a deadly malady. His affairs are in your hands to protect his interests. I must urge that you marry Paul at the earliest possible moment."

Eva scarcely knew what to say. "I can't," she blurted out, then tried to cover her confusion and made it worse, "only--as a last resort--to save my father--Oh--good-by!" And she almost ran from the room.

CHAPTER IX

Meanwhile, as Flint left Brent Rock, his fear of the Automaton returned to him with redoubled force. He had been false to his mission. Nor had he even succeeded in his treachery. A few minutes he had been certain that Eva would come to Baker's dock at the time set, but now doubts began to assail him. With her obvious faith in Locke, she might decide on the chemist's antidote, and there was always a possibility that it might restore Brent, in which case Flint realized that his life would be forfeit to the Automaton.