"I don't quite follow it yet," said Geoffrey.

"And yet it is simple," Tchigorsky replied. "Here is a form of electric battery in the vault connected by tiny wires to every sleeping chamber occupied by a Ravenspur. In each of these bed-rooms a powder is deposited somewhere and the wire leads to it. At a certain time, when you are all asleep, the current is switched on, the powder destroyed without leaving the slightest trace, and in the morning you are all as dead as if you had been placed in a lethal chamber—as a matter of fact, they would have been lethal chambers.

"Almost directly, by means of the chimneys, etc., the rooms would begin to draw a fresh supply of air, and by the time you were discovered everything would be normal again. Then the battery would be removed and the wires withdrawn without even the trouble of entering the rooms to fetch them. Then exit the whole family of Ravenspur, leaving behind a greater mystery than ever. Now do you understand what it all means?"

Geoffrey nodded and shuddered.

"What do you propose to do?" he asked. "Leave the battery where it is, and——"

"Unless I am mistaken, the battery is removed already," said the Russian.

He was correct. Investigation proved that the whole thing had been spirited away.

"As I expected," Tchigorsky muttered. "Done from the vaults under the sea, doubtless. That woman's servants keep very close to her. It is wonderful how they manage to slip about without being seen. They have ascertained that an accident has happened to their mistress, and they have removed signs of the conspiracy. But for the present they cannot remove their mistress."

Tchigorsky chuckled as he spoke.

"You seem pleased over that," said Geoffrey.

"Of course I am, my boy. It enables one to do a little burglary without the chance of being found out. And you are to assist me. But I am not going to start on my errand before midnight; so till then I shall stay here and smoke. At that hour you will please join me."

"I am to accompany you, then?"

"Yes, you are going to be my confederate in crime."

Geoffrey joined the others downstairs. Delight and thankfulness were written on every face. Never had Geoffrey found his family so tender and loving.

Usually, Marion had had her feelings under control, but to-night it seemed as if she could not make enough of her cousin. She hung over him, she lingered near him, until Vera laughingly proclaimed that jealousy was rendering her desperate.

"I cannot help it," Marion said half tearfully. "I am so glad. And if you only knew—but that does not matter. I am beside myself with joy."

"I suppose that woman upstairs is all right," Ravenspur said coldly.

He was by no means pleased that Mrs. May should have intruded twice in that way. And each time there had been some accident. With so much sorrow weighing him down and with the shadow of further disaster ever haunting him, Ravenspur was naturally suspicious.

It seemed absurd, no doubt, but that woman might be taking a hand against the family fortunes. The last occasion was bad enough, but this was many times worse. In the circumstances, as he pointed out, nothing could exceed the bad taste of this intrusion into a deserted house.

"She may not have known it," Mrs. Gordon said quietly. "Who knows but that she had discovered some plot against us and had come to warn us? Perhaps the enemy divined her intentions—hence the accident."

"But was it an accident?" Geoffrey asked.

"Something mysterious, like everything that occurs to us," his wife replied. "At any rate, she is breathing regularly and quietly now, and her skin is moist and cool. Ralph said he had seen something like it in India before. He is convinced that she will be all right in the morning. Don't be angry, father."

Rupert Ravenspur constrained himself to smile.

"I will not forget what is due to my position and my hospitality, my dear," he said. "After Geoffrey's miraculous escape, after the heavy cloud of sorrow so unexpectedly raised, I cannot feel it in my heart to be angry with anybody. How did you manage to get away, Geoffrey?"

Geoffrey told his tale again. It was not nice to be compelled to invent facts in the face of an admiring family; but then the truth could not have been told without betraying Tchigorsky and blowing all his delicate schemes to the winds. He was not sorry when he had finished.

Marion wiped the tears from her eyes.

"It was Providence," she said. "Nothing more nor less."

"Little doubt of it," Gordon murmured. "Geoff, have you any suspicions?"

"I know who did it, if that is what you mean," Geoffrey said, "and so does Marion."

The girl started. Her nerves were in such a pitiable condition that any little thing set them vibrating like the strings of a rudely handled harp.

"If I did I should have spoken," she said.

"Then you have not guessed?" Geoffrey smiled. "The masts and the sculls were sawn by a girl in a blue dress and red tam-o'-shanter cap. The girl who is so like——"

He did not complete the sentence; there was something in Marion's speaking eyes that asked him not to do so. Why he could not tell; but there was nothing to be gained by what was little less than a breach of confidence.

"What does it mean, Marion?" Ravenspur asked.

"Geoffrey and I saw such a girl not long before Geoff set out on his eventful voyage," Marion explained quietly. All the fear had gone out of her eyes; she met the gaze of the speaker tranquilly. "She passed me as I was painting; I have been close to her once before. But I don't understand why Geoff is so certain that the mysterious visitor tried to drown him."

"I've no proof," Geoffrey replied. "It is merely an instinct."

As a matter of fact, he had plenty of proof. Had he not seen the girl hastening away from his boat? Had he not seen her return after the boat had been beached and mourn over the wreck like some creature suffering from deep remorse?

But of this he could say nothing. To speak of it would be to betray the fact that Tchigorsky was still alive and active in pursuit of the foe.

"That woman can be found," Ravenspur said sternly.

"I doubt it," said Geoffrey. "She has a way of disappearing that is remarkable. You see her one moment and the next she has vanished. But I am certain that she is at the bottom of the mischief."

And Geoffrey refused to say more. As a matter of fact, nobody seemed to care to hear anything further. They were worn out with anxiety and exertion. They had had little food that day; the weary hours on the beach had exhausted them.

"For the present we can rest and be thankful," Ravenspur said as he rose to go. "We can sleep with easy minds to-night."

They moved off after him, all but Geoffrey and Vera. Mrs. Gordon could still be heard moving about one of the drawing rooms. Marion had slipped off unobserved. She hardly felt equal to bidding Geoffrey good-night. The tender smile was still on her face as she crept upstairs.

Then when she reached her room it faded away. She flung herself across the bed and burst into a passionate fit of weeping. And then gradually she sobbed herself into a heavy yet uneasy slumber.

"Well, I suppose I must go, too?" Vera said, tired out, yet reluctant to leave her lover. "Tell me what it means, Geoff?"

"Have I not already explained to you, darling?"

"Yes, but I don't believe one word of it," Vera replied. A kiss sufficed to wash the bitterness of the candor away. "I don't believe you were picked up by a yacht. I don't believe that you were in any danger. I don't understand it."

"Then we are both in the same state of benighted ignorance," Geoffrey smiled. "You are right not to believe me, dearest, but I had to tell the story and I had to play a part. It is all in the desperate game we are playing against our secret foe. For the present I am a puppet in the hands of abler men than myself. What I am doing will go far to set us free later."

Vera sighed gently. She sidled closer to her lover. Mrs. Gordon was coming out of the drawing room, a sign that Vera would have to go.

"I feel that I don't want to part with you again," she whispered, her eyes looking into his and her arm about him. "I feel as if I had nearly lost you. And if I did lose you, darling, what would become of me?"

Geoffrey kissed the quivering lips tenderly.

"Have no fear, sweetheart," he said; "all is coming right. See how those people have been frustrated over and over again. They have come with schemes worthy of Satan himself and yet they have failed. And it has been so arranged that those failures seem to be the result of vexatious accident. But they are not. And they will fail again and again until the net is around them and we shall be free. Darling, you are to sleep in peace to-night."

With a last fond embrace Vera slipped from her lover's side. She smiled at him brightly from the doorway and was gone. Geoffrey lighted a cigarette that presently dropped from his fingers and his head fell forward.

He started suddenly; the cigarette smelt pungently as it singed the carpet. Somebody was whispering his name; somebody was calling him from the stairs. Then he recognized Ralph's croaking voice.

"Tchigorsky," he muttered sleepily. "I had forgotten that Tchigorsky wanted me."