"He came to me, he was going to arrest me to-night, but I got him."

"Sit down," he said firmly, "and try to be coherent, Hilda. Who came to you?"

"Beale. He came to my boarding-house and wanted to know where you had taken Oliva Cresswell. Have you taken her?" she asked earnestly.

"Go on," he said.

"He came to me full of arrogance and threats. He was going to have me arrested, Julius, because of those letters which I gave you. But I didn't worry about myself, Julius. It was all for you that I thought.

The thought that you, my dear, great man, should be put in one of these horrible English prisons--oh, Julius!"

She rose, her eyes filled with tears, but he stood over her, laid his hands on her shoulders and pressed her back.

"Now, now. You must tell me everything. This is very serious. What happened then?"

"He wanted me to take him to one of the places."

"One of what places?" he asked quickly.

"I don't know. He only said that he knew that you had other houses--I don't even know that he said that, but that was the impression that he gave me, that he knew you were to be found somewhere."

"Go on," said the doctor.

"And so I thought and I thought," said the girl, her hands clasped in front of her, her eyes looking up into his, "and I prayed God would give me some idea to help you. And then the scheme came to me, Julius. I said I would lead him to you."

"You said you would lead him to me?" he said steadily, "and where did you lead him?"

"To the factory in Paddington," she said.

"There!" he stared at her.

"Wait, wait, wait!" she said, "oh, please don't blame me! I took him into the passage with the doors. I borrowed his light, and after we had passed and locked the second door I slipped through the third and slammed it in his face."

"Then----"

"He is there! Caught! Oh, Julius, did I do well? Please don't be angry with me! I was so afraid for you!"

"How long have you been here?" he asked.

"Not ten minutes, perhaps five minutes, I don't know. I have no knowledge of time. I came straight back to see you."

He stood by the table, gnawing his finger, his head bowed in concentrated thought.

"There, of all places!" he muttered; "there, of all places!"

"Oh, Julius, I did my best," she said tearfully.

He looked down at her with a little sneer.

"Of course you did your best. You're a woman and you haven't brains."

"I thought----"

"You thought!" he sneered. "Who told you you could think? You fool!

Don't you know it was a bluff, that he could no more arrest me than I could arrest him? Don't you realize--did he know you were in the habit of coming here?"

She nodded.

"I thought so," said van Heerden with a bitter laugh. "He knows you are in love with me and he played upon your fears. You poor little fool!

Don't cry or I shall do something unpleasant. There, there. Help yourself to some wine, you'll find it in the tantalus."

He strode up and down the room.

"There's nothing to be done but to settle accounts with Mr. Beale," he said grimly. "Do you think he was watched?"

"Oh no, no, Julius"--she checked her sobs--"I was so careful."

She gave him a description of the journey and the precautions she had taken.

"Well, perhaps you're not such a fool after all."

He unlocked a drawer in his desk and took out a long-barrelled Browning pistol, withdrew the magazine from the butt, examined and replaced it, and slipped back the cover.

"Yes, I think I must settle accounts with this gentleman, but I don't want to use this," he added thoughtfully, as he pushed up the safety-catch and dropped the weapon in his pocket; "we might be able to gas him. Anyway, you can do no more good or harm," he said cynically.

She was speechless, her hands, clasped tightly at her breast, covered a damp ball of handkerchief, and her tear-stained face was upturned to his.

"Now, dry your face." He stooped and kissed her lightly on the cheek.

"Perhaps what you have done is the best after all. Who knows? Anyway,"

he said, speaking his thoughts aloud, "Beale knows about the Green Rust and it can't be very long before I have to go to earth, but only for a little time, my Hilda." He smiled, showing his white teeth, but it was not a pleasant smile, "only for a little time, and then," he threw up his arms, "we shall be rich beyond the dreams of Frankfurt."

"You will succeed, I know you will succeed, Julius," she breathed, "if I could only help you! If you would only tell me what you are doing! What is the Green Rust? Is it some wonderful new explosive?"

"Dry your face and go home," he said shortly, "you will find a detective outside the door watching you, but I do not think he will follow you."

He dismissed the girl and followed her after an interval of time, striding boldly past the shadow and gaining the cab-stand in Shaftesbury Avenue without, so far as he could see, being followed. But he dismissed the cab in the neighbourhood of Baker Street and continued his journey on foot. He opened the little door leading into the yard but did not follow the same direction as the girl had led Stanford Beale. It was through another door that he entered the vault, which at one time had been the innocent repository of bubbling life and was now the factory where men worked diligently for the destruction of their fellows.

CHAPTER XXIV

THE GREEN RUST FACTORY

Stanford Beale spent a thoughtful three minutes in the darkness of the cellar passage to which Hilda Glaum had led him and then he began a careful search of his pockets. He carried a little silver cigar-lighter, which had fortunately been charged with petrol that afternoon, and this afforded him a beam of adequate means to take note of his surroundings.

The space between the two locked doors was ten feet, the width of the passage three, the height about seven feet. The roof, as he had already noted, was vaulted. Now he saw that along the centre ran a strip of beading. There had evidently been an electric light installation here, probably before the new owners took possession, for at intervals was a socket for an electric bulb. The new occupants had covered these and the rest of the wall with whitewash, and yet the beading and the electric fittings looked comparatively new. One wall, that on his left as he had come in, revealed nothing under his close inspection, but on the right wall, midway between the two doors, there had been a notice painted in white letters on a black background, and this showed faintly through the thick coating of distemper which had been applied. He damped a handkerchief with his tongue and rubbed away some of the whitewash where the letters were least legible and read: