thought to himself, otherwise I'd never stay alive.

"We've got him bracketed now," HQ said. "If we lose him now, he's a magician."

Sir Lewis walked on, seemingly oblivious to the group of men who had surrounded him. He came to the end of Fenchurch Street and looked to his left, towards London Bridge. Then he glanced to his right.

"I think he's looking for a cab," Houston whispered.

"That's what MacGruder says," came the reply. "We've got Arthmore in a cab behind you; he'll pick you up. MacGruder will get another cab, and we have a private car for Bogart."

Sir Lewis flagged a cab, climbed in, and gave an address to the driver. Houston didn't hear it, but MacGruder, a heavy-set, short, balding man, was standing near enough to get the instructions Sir Lewis had given to the driver.

A cab pulled up to the curb near Houston, and he got in.

Arthmore, the driver, was a thin, tall, hawknosed individual who could have played Sherlock Holmes on TV. Once he got into character for a part, he never got out of it unless absolutely necessary. Right now, he was a Cockney cab-driver, and he would play the part to the hilt.

"Where to, guv'nor?" he asked innocently.

"Buckingham Palace," said Houston. "I've got a poker appointment with Prince Charles."

"Blimey, guv'nor," said Arthmore. "You are movin' in 'igh circles! 'Ow's 'Er Majesty these days?"

The turboelectric motor hummed, and the cab shot off into traffic. "According to the report I get on the blinkin' wireless," he continued, "a chap named MacGruder claims that the eminent Sir Lewis 'Untley is 'eaded for Number 37 Upper Berkeley Mews."

"One of these days," said Houston, "all those H's you drop is going to bounce back and hit you in the face."

"Beg pardon, Mr. Yewston?" Arthmore asked blankly.

Houston grinned. "Nothing, cabbie; it's just that you remind me of a cultured, intelligent fellow named Jack Arthmore. The only difference is that Jack speaks the Queen's English."

"Crikey!" said Arthmore. "Wot a coincidence!" He paused, then: "The Queen's English, you say? She 'as to be, don't she?"

"Shut up," said Houston conversationally. "And give me a cigarette," he added.

"There's a package of Players in my shirt pocket," Arthmore said, keeping his hands on the wheel.

Houston fished out a cigarette, lit it, and returned the pack.

Apropos of nothing, Arthmore said: "Reminds me of the time I was workin' for a printer, see? We 'ad to print up a bunch of 'andbills advertisin' a church charity bazaar. Down at the bottom was supposed to be printed 'Under the auspices of St. Bede's-on-Thames.' So I—"

He went on with a long, rambling tale about making a mistake in printing the handbill. Houston paid little attention. He smoked in silence, keeping his eyes on the red glow of the taillight ahead of them.

Neither man mentioned the approaching climax of the chase. Even hardened veterans of the Psychodeviant Police don't look forward to the possibility of having their minds taken over, controlled by some outside force.

It had never happened to Houston, but he knew that Arthmore had been through the experience once. It evidently wasn't pleasant.

"—and the boss was 'oppin' mad," Arthmore was saying, "but, crikey, 'ow was I to know that auspice was spelled A-U-S-P-I-C-E?"

Houston grinned. "Yeah, sure. How're we doing with Sir Lewis?"

"Seems to be headed in the right direction," Arthmore said, suddenly dropping the Cockney accent. "This is the route I'd take if I were headed for Upper Berkeley Mews. He probably hasn't told the driver to change addresses—maybe he won't."

"The victims never do," Houston said. "He probably is actually headed toward Number 37 Upper Berkeley Mews."

"Yeah. Nobody's perfect," said Arthmore.

Forty-five minutes of steady progress through the streets of Greater London brought Sir Lewis Huntley to Upper Berkeley and to the short dead-end street which constituted the Mews. By the time the dapper baronet stepped out of the machine and paid his driver, the whole area was surrounded by and filled with the well-armed, silent, and careful agents of the Psychodeviant Police.

Number 37 was an old concrete-and-steel structure of the George VI period, faced with a veneer of red brick. It had obviously been remodeled at least once to make the façade more modern and more fashionable; the red-violet anodized aluminum was relatively fresh and unstained. It wouldn't have taken vast wealth to rent a flat in the building, but neither would an average income have been quite enough.

Houston looked out of the window of Arthmore's cab and glanced at the tiers of windows in the building. Presumably, the man they were looking for was up there—somewhere.

So you occupy a station in the upper middle-class, thought Houston. It checked. Every bit of evidence that came his way seemed to check perfectly and fit neatly into the hypothesis which he had formed. Soon it would be time to test that theory—but the time had not yet come.

"Stand by and wait for orders, Houston," said the speaker in Houston's ear. "We've got men inside the building."

Sir Lewis Huntley opened the sparkling, translucent door of Number 37 Upper Berkeley Mews and went inside.

Arthmore pulled the cab over to the curb a few yards from the entrance and the two men waited in silence. All around them were other men, some in private cars, some walking slowly along the street. All of them were part of the net that had gathered to catch one man.

Poor fish, Houston thought wryly.

There was no noise, no excitement. Five minutes after Sir Lewis had entered the front door, it opened again. A man whom Houston had never seen before stepped out and gestured with one hand. At the same time, Houston's speaker said: "They've got him. Hit him with a stun gun when he tried to get out through the fire exit."

An ambulance which had been waiting at the entrance of the Mews pulled up in front of Number 37, and a minute or so later a little clot of men came out bearing a stretcher, which was loaded into the ambulance. Immediately after them came another man who had a firm, but polite grip on the arm of Sir Lewis Huntley.

Houston sighed and leaned back in his seat. That was that. It was all over. Simple. Nothing to it.

Another Controller had been apprehended by the Psychodeviant Police. Another deviant, already tried and found guilty, was ready to be exiled from Earth and imprisoned on one of the Penal Asteroids. All in the day's work.

There's just one thing I'd like to know, Houston thought blackly. What in the hell's going on?

In his hotel room near Piccadilly Circus, several hours later, David Houston sat alone, drink in hand, and put that same question to himself again.

"What's going on?"

On the face of it, it was simple. On the face of it, the answer was right in front of him, printed in black and white on the front page of the evening Times.

Houston lifted the paper off the bed and looked at it. The banner line said: Controller Captured in Lambeth!

Beneath that, in smaller type, the headline added: Robert Harris Accused of Taking Control of Barrister Sir Lewis Huntley.

The column itself told the whole story. Mr. Robert Harris, of No. 37 Upper Berkeley Mews, had, by means of mental control, taken over the mind of Sir Lewis and compelled him to draw one thousand pounds out of his bank. While Sir Lewis was returning to Harris with the money, the United Nations Psychodeviant Police had laid a trap. Sir Lewis, upon recovering his senses when Harris was rendered unconscious by a stun gun, had given evidence to the PD Police and to officials at New Scotland Yard.

Houston looked at the full-color photo of Harris that was printed alongside the column. Nice-looking chap; late twenties or early thirties, Houston guessed. Blond-red hair, blue eyes.