"I'm Milsom," said the man in the doorway again.

His clothes were grimed and dusty, his collar limp and soiled. There were two days' growth of red-grey stubble on his big jaw, and he bore himself like a man who was faint from lack of sleep.

He walked unsteadily to the table and fell into a chair.

"Where is van Heerden?" asked Beale, but Milsom shook his head.

"I left him two hours ago, after a long and unprofitable talk on patriotism," he said, and laughed shortly. "At that time he was making his way back to his house in Southwark."

"Then he is in London--here in London!"

Milsom nodded.

"You won't find him," he said brusquely. "I tell you I've left him after a talk about certain patriotic misgivings on my part--look!"

He lifted his right hand, which hitherto he had kept concealed by his side, and Oliva shut her eyes and felt deathly sick.

"Right index digit and part of the phalanges shot away," said Milsom philosophically. "That was my trigger-finger--but he shot first. Give me a drink!"

They brought him a bottle of wine, and he drank it from a long tumbler in two great breathless gulps.

"You've closed the coast to him," he said, "you shut down your wires and cables, you're watching the roads, but he'll get his message through, if----"

"Then he hasn't cabled?" said Beale eagerly. "Milsom, this means liberty for you--liberty and comfort. Tell us the truth, man, help us hold off this horror that van Heerden is loosing on the world and there's no reward too great for you."

Milsom's eyes narrowed.

"It wasn't the hope of reward or hope of pardon that made me break with van Heerden," he said in his slow way. "You'd laugh yourself sick if I told you. It was--it was the knowledge that this country would be down and out; that the people who spoke my tongue and thought more or less as I thought should be under the foot of the Beast--fevered sentimentality! You don't believe that?"

"I believe it."

It was Oliva who spoke, and it appeared that this was the first time that Milsom had noticed her presence, for his eyes opened wider.

"You--oh, you believe it, do you?" and he nodded.

"But why is van Heerden waiting?" asked McNorton. "What is he waiting for?"

The big man rolled his head helplessly from side to side, and the hard cackle of his laughter was very trying to men whose nerves were raw and on edge.

"That's the fatal lunacy of it! I think it must be a national characteristic. You saw it in the war again and again--a wonderful plan brought to naught by some piece of over-cleverness on the part of the super-man."

A wild hope leapt to Beale's heart.

"Then it has failed! The rust has not answered----?"

But Milsom shook his head wearily.

"The rust is all that he thinks--and then some," he said. "No, it isn't that. It is in the work of organization where the hitch has occurred. You know something of the story. Van Heerden has agents in every country in the world. He has spent nearly a hundred thousand pounds in perfecting his working plans, and I'm willing to admit that they are wellnigh perfect. Such slight mistakes as sending men to South Africa and Australia where the crops are six months later than the European and American harvests may be forgiven, because the German thinks longitudinally, and north and south are the two points of the compass which he never bothers his head about. If the Germans had been a seafaring people they'd have discovered America before Columbus, but they would never have found the North Pole or rounded the Cape in a million years."

He paused, and they saw the flicker of a smile in his weary eyes.

"The whole scheme is under van Heerden's hand. At the word 'Go' thousands of his agents begin their work of destruction--but the word must come from him. He has so centralized his scheme that if he died suddenly without that word being uttered, the work of years would come to naught. I guess he is suspicious of everybody, including his new Government. For the best part of a year he has been arranging and planning. With the assistance of a girl, a compatriot of his, he has reduced all things to order. In every country is a principal agent who possesses a copy of a simple code. At the proper moment van Heerden would cable a word which meant 'Get busy' or 'Hold off until you hear from me,' or 'Abandon scheme for this year and collect cultures.' I happen to be word-perfect in the meanings of the code words because van Heerden has so often drummed them into me."

"What are the code words?"

"I'm coming to that," nodded Milsom. "Van Heerden is the type of scientist that never trusts his memory. You find that kind in all the school--they usually spend their time making the most complete and detailed notes, and their studies are packed with memoranda. Yet he had a wonderful memory for the commonplace things--for example, in the plain English of his three messages he was word perfect. He could tell you off-hand the names and addresses of all his agents. But when it came to scientific data his mind was a blank until he consulted his authorities. It seemed that once he made a note his mind was incapable of retaining the information he had committed to paper. That, as I say, is a phenomenon which is not infrequently met with amongst men of science."

"And he had committed the code to paper?" asked Kitson.

"I am coming to that. After the fire at the Paddington works, van Heerden said the time had come to make a get away. He was going to the Continent, I was to sail for Canada. 'Before you go,' he said, 'I will give you the code--but I am afraid that I cannot do that until after ten o'clock.'"

McNorton was scribbling notes in shorthand and carefully circled the hour.

"We went back to his flat and had breakfast together--it was then about five o'clock. He packed a few things and I particularly noticed that he looked very carefully at the interior of a little grip which he had brought the previous night from Staines. He was so furtive, carrying the bag to the light of the window, that I supposed he was consulting his code, and I wondered why he should defer giving me the information until ten o'clock. Anyway, I could swear he took something from the bag and slipped it into his pocket. We left the flat soon after and drove to a railway ............