After all, it was for the best--van Heerden could almost see the hand of Providence in this deliverance of his enemy into his power. There must be a settlement with Beale, that play-acting drunkard, who had so deceived him at first.

Dr. van Heerden could admire the ingenuity of his enemy and could kill him. He was a man whose mental poise permitted the paradox of detached attachments. At first he had regarded Stanford Beale as a smart police officer, the sort of man whom Pinkerton and Burns turn out by the score. Shrewd, assertive, indefatigable, such men piece together the scattered mosaics of humdrum crimes, and by their mechanical patience produce for the satisfaction of courts sufficient of the piece to reveal the design. They figure in divorce suits, in financial swindles and occasionally in more serious cases.

Van Heerden knew instinctively their limitations and had too hastily placed Beale in a lower category than he deserved. Van Heerden came to his workroom by way of the buffet which he had established for the use of his employees. As he shut the steel door behind him he saw Milsom standing at the rough wooden sideboard which served as bar and table for the workers.

"This is an unexpected pleasure," said Milsom, and then quickly, as he read the other's face: "Anything wrong?"

"If the fact that the cleverest policeman in America or England is at present on the premises can be so described, then everything is wrong," said van Heerden, and helped himself to a drink.

"Here--in the laboratory?" demanded Milsom, fear in his eyes. "What do you mean?"

"I'll tell you," said the other, and gave the story as he had heard it from Hilda Glaum.

"He's in the old passage, eh?" said Milsom, thoughtfully, "well there's no reason why he should get out--alive."

"He won't," said the other.

"Was he followed--you saw nobody outside?"

"We have nothing to fear on that score. He's working on his own."

Milsom grunted.

"What are we going to do with him?"

"Gas him," said van Heerden, "he is certain to have a gun."

Milsom nodded.

"Wait until the men have gone. I let them go at three--a few at a time, and it wants half an hour to that. He can wait. He's safe where he is. Why didn't Hilda tell me? I never even saw her."

"She went straight up from the old passage--through the men's door--she didn't trust you probably."

Milsom smiled wryly. Though he controlled these works and knew half the doctor's secrets, he suspected that the quantity of van Heerden's trust was not greatly in excess of his girl's.

"We'll wait," he said again, "there's no hurry and, anyway, I want to see you about old man Heyler."

"Von Heyler? I thought you were rid of him?" said van Heerden in surprise, "that is the old fool that Beale has been after. He has been trying to suck him dry, and has had two interviews with him. I told you to send him to Deans Folly. Bridgers would have taken care of him."

"Bridgers can look after nothing," said Milsom.

His eyes roved along the benches and stopped at a worker at the farther end of the room.

"He's quiet to-night," he said, "that fellow is too full of himself for my liking. Earlier in the evening before I arrived he pulled a gun on Schultz. He's too full of gunplay that fellow--excuse the idiom, but I was in the same tailor's shop at Portland Gaol as Ned Garrand, the Yankee bank-smasher."

Van Heerden made a gesture of impatience.

"About old Heyler," Milsom went on, "I know you think he's dangerous, so I've kept him here. There's a room where he can sleep, and he can take all the exercise he wants at night. But the old fool is restless--he's been asking me what is the object of his work."

"He's difficult. Twice he has nearly betrayed me. As I told you in the car, I gave him some experimental work to do and he brought the result to me--that was the sample which fell into Beale's hands."

"Mr. Beale is certainly a danger," said Milsom thoughtfully.

Van Heerden made a move toward the laboratory, but Milsom's big hand detained him.

"One minute, van Heerden," he said, "whilst you're here you'd better decide--when do we start dismantling? I've got to find some excuse to send these fellows away."

Van Heerden thought.

"In two days," he said, "that will give you time to clear. You can send the men--well, send them to Scotland, some out-of-the-way place where news doesn't travel. Tell them we're opening a new factory, and put them up at the local hotel."

Milsom inclined his head.

"That sounds easy," he said, "I could take charge of them until the time came to skip. One can get a boat at Greenock."

"I shall miss you," said van Heerden frankly, "you were necessary to me, Milsom. You're the driving force I wanted, and the only man of my class and calibre I can ever expect to meet, one who would go into this business with me."

They had reached the big vault and van Heerden stood regarding the scene of mental activity with something approaching complacency.

"There is a billion in process of creation," he said.

"I could never think in more than six figures," said Milsom, "and it is only under your cheering influence that I can stretch to seven. I am going to live in the Argentine, van Heerden. A house on a hill----"

The other shivered, but Milsom went on.

"A gorgeous palace of a house, alive with servants. A string band, a perfectly equipped laboratory where I can indulge my passion for research, a high-powered auto, wine of the rarest--ah!"

Van Heerden looked at his companion curiously.

"That appeals to you, does it? For me, the control of finance. Endless schemes of fortune; endless smashings of rivals, railways, ships, great industries juggled and shuffled--that is the life I plan."

"Fine!" said the other laconically.

They walked to a bench and the ............