"No time for explanations now," she answered quickly. "We must get out of here."

He recalled the patter of hastening feet, the soft closing of the door.

In the growing light he saw its tin-sheeted face flush with the wall.

"The door has been shut," he said. "I'm afraid--locked. Why did you light that fire?"

She ran across, grasped the k.n.o.b, then commenced to beat with her fists at the tin. Suddenly she stopped. Her shoulders drooped.

"No use," she whispered. "She must have come in. She won't open now."

Garth hurried to her side.

"I don't understand," he said, "but it's evident we are caught here, and that fire has been fixed--a signal?"

She nodded.

"Why did you light it?"

"Because," she answered dully, "it had to burn to-night."

The crisis they faced was clear to him.

"Nora! In a minute this room will be a furnace."

He imagined from the excitement still flashing in her eyes that she did not quite realize, but she spoke without regret, and her words carried the shocking fatality of the German's.

"I'm sorry, Jim, but if I had known we would be caught I would have lighted it just the same. After all, a small price in the long run--only the two of us."

He brushed the rapid perspiration from his face. The fire had reached the heart of the pile. The air thickened with a reddish, pungent smoke.

He choked.

"I'm sorry, Jim. I came only to help you, but I found--"

The vapour cut her voice.

The sentimental possibilities of their predicament came with a gentle wonder to Garth. They over-weighed the danger, robbed him for the moment of full comprehension. This clearly was his moment, and whatever the next might bring seemed a fair exchange for her probable response. He reached blindly towards her through the smoke.

"Nora!"

His heart leapt as she swayed a little. Then he heard the grating of the key in the lock. It impressed him as curious that the saving sound carried to him a sense of disappointment, the emptiness of a destiny unfulfilled.

Nora turned the k.n.o.b. He pushed against the door. They stumbled into the next room, breathing deeply the fresh, clean air.

Alden's prostrate form lay just within. His wife stood across the room by the hall door, the revolver held listlessly in her hand. Her hair, more than ever disordered, fell about her weary eyes, and gave her face an air of ironical witchery.

Garth caught the meaning of the tableau. He glanced with admiration at the sick man, appreciating the bitter obstacle he had overcome, the abhorrent chance he had taken after conquering his physical incapacity and reaching the door. The result, Garth noticed, had carried to Alden a vast relief, a shadow of content. The light from the conservatory flickered about his face, exposing an expression of pride. The silent lips moved as if to frame a boast.

"So, Mrs. Alden," Garth said, "you left him again. To warn the others?"

She did not answer. He shrugged his shoulders.

"Anyway," he went on, "when you came back and found him at the key you didn't have time to get to him, and you weren't quite as bad as you should have been. You let him unlock the door. You didn't have the nerve to shoot--your husband."

"Don't, Jim," Nora warned. "You don't understand."

Frankly he didn't, but he knew that Mrs. Alden, in a sense, still controlled the situation. Her revolver could compel their movements. Its explosion would doubtless bring help swarming to her side.

"And you see," Nora went on, speaking to her gently, "what a useless sacrifice it would have been. Everything was finished for you the moment I lighted the beacon."

Mrs. Alden nodded.

Garth grinned as the protective feminine instinct expressed itself through this woman in her most intricate hour.

"It was all arranged," she said. "If you will close that door the house will be safe enough from the fire."

She indicated her husband. There were tears in her eyes again.

"You will take care of him?"

"Yes," Nora said.

She turned and closed the door. Through the sudden darkness Garth heard Mrs. Alden run into the hall. He sprang after her, but Nora's voice, sharp and commanding, halted him.

"Let her go, Jim. I'll explain. Light the lamp now."

"You've earned the right to give the orders," he said.

He felt his way to the writing-table and lighted the lamp.

"You know," he said, "that there are many men near here--that they can trap us in this house?"

"I don't think," she answered, "that they will come to this house again."

He turned to her.

"Nora! What is it? Even after all I've seen I can't be sure. The furnaces? They are two miles away."

She shook her head.

"Not the furnaces, Jim. Come with me and I will show you."

She led him to an unlighted room across the hall and flung back the curtains.

The glare of a conflagration, far vaster than that which had threatened them in the conservatory, flashed in their eyes and lighted the neighborhood with a brilliancy fiercer than noonday.

For the first time Garth could see that the house stood on a high, wooded plateau. The trees had been cleared away between it and the water, and a slope, bordered with hedges, had been blasted to a beach, small and crescent-shaped. The fire blazed with a destructive violence in a structure on this beach. He recalled the driver's gossip about Alden's yacht. He saw a small launch, heavily-laden, making for the open sea.

"The boat house," he said.