Dr. van Heerden did not hurry his departure from his Staines house. He spent the morning following Oliva's marriage in town, transacting certain important business and making no attempt to conceal his comings and goings, though he knew that he was shadowed. Yet he was well aware that every hour that passed brought danger nearer. He judged (and rightly) that his peril was not to be found in the consequences to his detention of Oliva Cress well.

"I may have a week's grace," he said to Milsom, "and in the space of a week I can do all that I want."

He spent the evening superintending the dismantling of apparatus in the shed, and it was past ten o'clock on Tuesday before he finished.

It was not until he was seated by Milsom's side in the big limousine and the car was running smoothly through Kingston that he made any further reference to the previous afternoon.

"Is Beale content?" he asked.

"Eh?"

Milsom, dozing in the corner of the car, awoke with a start.

"Is Beale content with his prize--and his predicament?" asked van Heerden.

"Well, I guess he should be. That little job brings him a million. He shouldn't worry about anything further."

But van Heerden shook his head.

"I don't think you have things quite right, Milsom," he said. "Beale is a better man than I thought, and knows my mind a little too well. He was astounded when Homo claimed to be a priest--I never saw a man more stunned in my life. He intended the marriage as a bluff to keep me away from the girl. He analysed the situation exactly, for he knew I was after her money, and that she as a woman had no attraction for me. He believed--and there he was justified--that if I could not marry her I had no interest in detaining her, and engaged Homo to follow him around with a special licence. He timed everything too well for my comfort."

Milsom shifted round and peered anxiously at his companion.

"How do you mean?" he asked. "It was only by a fluke that he made it in time."

"That isn't what I mean. It is the fact that he knew that every second was vital, that he guessed I was keen on a quick marriage and that to forestall me he carried his (as he thought) pseudo-clergyman with him so that he need not lose a minute: these are the disturbing factors."

"I don't see it," said Milsom, "the fellow's a crook, all these Yankee detectives are grafters. He saw a chance of a big rake off and took it, fifty-fifty of a million fortune is fine commission!"

"You're wrong. I'd like to think as you do. Man! Can't you see that his every action proves that he knows all about the Green Rust?"

"Eh?"

Milsom sat up.

"How--what makes you say that?"

"It's clear enough. He has already some idea of the scheme. He has been pumping old Heyler; he even secured a sample of the stuff--it was a faulty cultivation, but it might have been enough for him. He surmised that I had a special use for old Millinborn's money and why I was in a hurry to get it."

The silence which followed lasted several minutes.

"Does anybody except Beale know? If you settled him...?"

"We should have to finish him to-night" said van Heerden, "that is what I have been thinking about all day."

Another silence.

"Well, why not?" asked Milsom, "it is all one to me. The stake is worth a little extra risk."

"It must be done before he finds the Paddington place; that is the danger which haunts me." Van Heerden was uneasy, and he had lost the note of calm assurance which ordinarily characterized his speech. "There is sufficient evidence there to spoil everything."

"There is that," breathed Milsom, "it was madness to go on. You have all the stuff you want, you could have closed down the factory a week ago."

"I must have a margin of safety--besides, how could I do anything else? I was nearly broke and any sign of closing down would have brought my hungry workers to Krooman Mansions."

"That's true," agreed the other, "I've had to stall 'em off, but I didn't know that it was because you were broke. It seemed to me just a natural reluctance to part with good money."

Further conversation was arrested by the sudden stoppage of the car. Van Heerden peered through the window ahead and caught a glimpse of a red lamp.

"It is all right," he said, "this must be Putney Common, and I told Gregory to meet me with any news."

A man came into the rays of the head-lamp and passed to the door.

"Well," asked the doctor, "is there any trouble?"

"I saw the green lamp on the bonnet," said Gregory (Milsom no longer wondered how the man had recognized the car from the score of others which pass over the common), "there is no news of importance."

"Where is Beale?"

"At the old man's hotel. He has been there all day."

"Has he made any further visits to the police?"

"He was at Scotland Yard this afternoon."

"And the young lady?"

"One of the waiters at the hotel, a friend of mine, told me that she is much better. She has had two doctors."

"And still lives?" said the cynical Milsom. "That makes four doctors she has seen in two days."

Van Heerden leant out of the car window and lowered his voice.

"The Fraeulein Glaum, you saw her?"

"Yes, I told her that she must not come to your laboratory again until you sent for her. She asked when you leave."

"That she must not know, Gregory--please remember."

He withdrew his head, tapped at the window and the car moved on.

"There's another problem for you, van Heerden," said Milsom with a chuckle.

"What?" demanded the other sharply.

"Hilda Glaum. I've only seen the girl twice or so, but she adores you. What are you going to do with her?"

Van Heerden lit a cigarette, and in the play of the flame Milsom saw him smiling.

"She comes on after me," he said, "by which I mean that I have a place for her in my country, but not----"

"Not the sort of place she expects," finished Milsom bluntly. "You may have trouble there."

"Bah!"

"That's foolish," said Milsom, "the convict establishments of England are filled with men who said 'Bah' when they were warned against jealous women. If," he went on, "if you could eliminate jealousy from the human outfit, you'd have half the prison warders of England unemployed."

"Hilda is a good girl," said the other complacently, "she is also a good German girl, and in Germany women know their place in the system. She will be satisfied with what I give her."

"There aren't any women like that," said Milsom with decisio............