The inspector said in astonishment, "You know who did it?"

"We can guess," Harris said. "We think he's killed twice before. If it's the same man, we know who he is but not where he is."

"What with the restricted area so close," the inspector said, "and Special Branch and M15 arriving on the scene so quick, is there anything else I need to know about this case?"

Harris answered, "Just that you keep very quiet until your chief constable has talked to our people."

"Found anything else, inspector?" Bloggs asked.

"We're still going over the area, and in ever-widening circles; but nothing so far. There were some clothes in the grave." He pointed. Bloggs touched them gingerly; black trousers, a black sweater, a short black leather jacket, RAF-style. "Clothes for night work," Harris said.

"To fit a big man," Bloggs added.

"How tall is your man?"

"Over six foot."

The inspector said, "Did you pass the men who found the sunken boat?"

"Yes," Bloggs frowned. "Wbere's the nearest lock?"

"Four miles upstream."

"If our man was in a boat, the lock-keeper must have seen him, mustn't he?"

"Must have," the inspector agreed.

Bloggs said, "We'd better talk to him." He returned to his bicycle.

"Not another four miles," Harris complained.

"Work off some of those Sunday dinners," Bloggs told him.

The four-mile ride took them most of an hour. The towpath was made for horses, not wheels, and it was uneven, muddy, and mined with loose boulders and tree roots. Harris was sweating and cursing by the time they reached the lock.

The lock-keeper was sitting outside his little house, smoking a pipe and enjoying the mild afternoon air. He was a middle-aged man of slow speech and slower movements. He regarded the two cyclists with some amusement.

Bloggs spoke, because Harris was out of breath. "We're police officers," he said.

"Is that so?" said the lock-keeper. "What's the excitement?" He looked as excited as a cat in front of a fire.

Bloggs took the photograph of Die Nadel out of his wallet and gave it to the man. "Have you ever seen him?"

The lock-keeper put the picture on his lap while he held a fresh match to his pipe. Then he studied the photograph for a while, and handed it back. "Well?" Harris said.

"Aye. He was here about this time yesterday. Came in for a cup of tea. Nice enough chap. What's he done, shown a light after blackout?"

Bloggs sat down heavily. "That clinches it," he said.

Harris thought aloud. "He moors the boat downstream from here and goes into the restricted area after dark." He spoke quietly, so that the lock-keeper would not hear. "When he comes back, the Home Guard has his boat staked out. He deals with them, sails a bit further to the railway, scuttles his boat and... hops a train?"

Bloggs said to the lock-keeper: "The railway line that crosses the canal a few miles downstream-where does it go?"

"London."

Bloggs said, "Oh, shit."

Bloggs got back to the War Office in Whitehall at midnight. Godliman and Billy Parkin were there waiting for him. Bloggs said, "It's him, all right," and told them the story.

Parkin was excited, Godliman just looked tense. When Bloggs had finished, Godliman said: "So now he's back in London, and we're looking for, in more ways than one, a needle in a haystack again." He was playing with matches, forming a picture with them on his desk. "Do you know, every time I look at that photograph I get the feeling I've actually met the damn fellow."

"Well, think, for God's sake," Bloggs said. "Where?"

Godliman shook his head in frustration. "It must have been only once, and somewhere strange. It's like a face I've seen in a lecture audience, or in the background at a cocktail party. A fleeting glimpse, a casual encounter. When I remember it probably won't do us any good."

Parkin said, "What's in that area?"

"I don't know, which means it's probably highly important," Godliman said.

There was a silence. Parkin lit a cigarette with one of Godliman's matches. Bloggs looked up. "We could print a million copies of his picture; give one to every policeman, ARP warden, member of the Home Guard, serviceman, railway porter; paste them up on boardings and publish them in the papers..."

Godliman shook his head. "Too risky. What if he's already talked to Hamburg about whatever he's seen? If we make a public fuss about the man they'll know that his information is good. We'd only be lending credence to him."

"We've got to do something."

"We'll circulate his picture to police officers. We'll give his description to the press and say he's just a conventional murderer. We can give the details of the Highgate and Stockwell murders, without saying that security is involved."

Parkin said, "what you're saying is, we have to fight with one hand tied behind our back."

"For now anyway."

"I'll start the ball rolling with the Yard," Bloggs said. He picked up the phone.

Godliman looked at his watch. "There's not much more we can do tonight, but I don't feel like going home. I shan't sleep."

Parkin stood up. "In that case, I'm going to find a kettle and make some tea." He went out.

The matches on Godliman's desk made a picture of a horse and carriage. He took away one of the horse's legs and lit his pipe with it. "Have you got a girl, Fred?" he asked conversationally.

"No."

"Not since?"

"No."

Godliman puffed at his pipe. "There has to be an end to bereavement, you know."

Bloggs made no reply.

Godliman said, "Look, perhaps I shouldn't talk to you like a Dutch uncle. But I know how you feel; I've been through it myself. The only difference was that I didn't have anyone to blame."

"You didn't remarry," Bloggs said, not looking at Godliman.

"No, and I don't want you to make the same mistake. When you reach middle age, living alone can be very depressing."

"Did I ever tell you they called her Fearless Bloggs?"

"Yes, you did."

Bloggs finally looked at Godliman. "Tell me, where in the world will I find another girl like that?"

"Does she have to be a hero?"

"After Christine..."

"England is full of heroes, Fred."

At that moment Colonel Terry walked in. "Don't get up, gentlemen. This is important, listen carefully. Whoever killed those five Home Guards has learned a vital secret. There's an invasion coming, you know that. You don't know when or where. Needless to say, our objective is to keep the Germans in that same state of ignorance. Most of all, about where the invasion will come. We have gone to some extreme lengths to ensure that the enemy be misled in this matter. Now, it seems certain, he will not be if their man gets through. He has, it is definitely established, found out our deception. Unless we stop him from delivering his news, the entire invasion-and therefore, one can safely say, the war-is compromised. I've already told you more than I wanted to, but it's imperative that you understand the urgency and precise consequences of failure to stop the intelligence from getting through." He did not tell them that Normandy was the invasion site, nor that the Pas de Calais via Eeast Anglia the diversionary one, though he realised Godliman would surely conclude the latter once he had debriefed Bloggs on his efforts to trail the murderer of the Home Guardsmen.

Bloggs said: "Excuse me, but why are you so sure their man found out?"

Terry went to the door. "Come in, Rodriguez."

A tall, handsome man with jet-black hair and a long nose entered the room and nodded politely to Godliman and Bloggs. Terry said: "Senhor Rodriguez is our man at the Portuguese Embassy. Tell them what happened, Rodriguez."

The man stood by the door. "As you know, we have been watching Senhor Francisco of the embassy staff for some time. Today he went to meet a man in a taxi, and received an envelope. We relieved him of the envelope shortly after the man in the taxi drove off. We were able to get the licence number of the taxi."

"I'm having the cabbie traced," Terry said. "All right, Rodriguez, you'd better get back. And thank you."

The tall Portuguese left the room. Terry handed Godliman a large yellow envelope, addressed to Manuel Francisco. Godliman opened it- it had already been unsealed-and withdrew a second envelope marked with a meaningless series of letters: presumably a code.

Within the inner envelope were several sheets of paper covered with handwriting and a set of ten-by-eight photographs. Godliman examined the letter. "It looks like a very basic code," he said.

"You don't need to read it," Terry said impatiently. "Look at the photographs."

Godliman did so. There were about thirty of them, and he looked at each one before speaking. He handed them to Bloggs. "This is a catastrophe." Bloggs glanced through the pictures, then put them down.

Godliman said, "This is only his backup. He's still got the negatives, and he's going somewhere with them."

The three men sat still in the little office, like a tableau. The only illumination came from a spotlight on Godliman's desk. With the cream walls, the blacked-out window, the spare furniture and the worn Civil Service carpet, it was a prosaic backdrop for dramatics. Terry said, "I'm going to have to tell Churchill."

The phone rang, and the colonel picked it up. "Yes. Good. Bring him here right away, please, but before you do, ask him where he dropped the passenger. What? Thank you, get here fast." He hung up. "The taxi dropped our man at University College Hospital."

Bloggs said, "Perhaps he was injured in the fight with the Home Guard." Terry said, "Where is the hospital?"

"About five minuses' walk from Euston Station," Godliman said. "Trains from Euston go to Holyhead, Liverpool, Glasgow... all places from which you can catch a ferry to Ireland."

"Liverpool to Belfast," Bloggs said. "Then a car to the border across into Eire, and a U-boat on the Atlantic coast. Somewhere. He wouldn't risk Holyhead-to-Dublin because of the passport control, and there would be no point in going beyond Liverpool to Glasgow."

Godliman said, "Fred, you'd better go to the station and show the picture of Faber around, see if anyone noticed him getting on a train. I'll phone the station and warn them you're coming, and at the same time find out which trains have left since about ten thirty."

Bloggs picked up his hat and coat. "I'm on my way."

Godliman lifted the phone. "Yes, we're on our way."

There were still plenty of people at Euston Station. Although in normal times the station closed around midnight, wartime delays were such that the last train often had not left before the earliest milk train of the morning arrived. The station concourse was a mass of kitbags and sleeping bodies.

Bloggs showed the picture to three railway policemen. None of them recognised the face. He tried ten women porters: nothing. He went to every ticket barrier. One of the guards said, "We look at tickets, not faces." He tried half a dozen passengers without result. Finally he went into the ticket office and showed the picture to each of the clerks.

A very fat, bald clerk with ill-fitting false teeth recognised the face. "I play a game," he told Bloggs. "I try to spot something about a passenger that tells me why he's catching a train. Like, he might have a black tie for a funeral, or muddy boots means he's a farmer going home, or there might be a college scarf, or a white mark on a woman's finger where she's took off her wedding ring... know what I mean? Everybody got something. This is a dull job, not that I'm complaining-"

"What did you notice about this fellow?" Bloggs interrupted him.

"Nothing. That was it, see-I couldn't make him out at all. Almost like he was trying to be inconspicuous, know what I mean?"

"I know what you mean." Bloggs paused. "Now, I want you to think very carefully. Where was he going, can you remember?"

"Yes," said the fat clerk. "Inverness."

"That doesn't mean he's going there," said Godliman. "He's a professional-he knows we can ask questions at railway stations. I expect he automatically buys a ticket for the wrong destination." He looked at his watch. "He must have caught the 11:45. That train is now pulling into Stafford. I checked with the railway; they checked with the signalmen.

"They're going to stop the train this side of Crewe. I've got a plane standing by to fly you two to Stoke-on-Trent.

"Parkin, you'll board the train where it's stopped, outside Crewe. You'll be dressed as a ticket inspector, and you'll look at every ticket and every face on that train. When you've spotted Faber, just stay close to him.

"Bloggs, you'll be waiting at the ticket barrier at Crewe, just in case Faber decides to hop off there. But he won't. You'll get on the train, and be first off at Liverpool, and waiting at the ticket barrier for Parkin and Faber to come off it. Half the local constabulary will be there to back you up."

"That's all very well if he doesn't recognise me," Parkin said. "What if he remembers my face from Highgate?"

Godliman opened a desk drawer, took out a pistol, and gave it to Parkin. "If he recognises you, shoot him." Parkin pocketed the weapon without comment.

Godliman said: "You heard Colonel Terry, but I want to emphasise the importance of all this. If we don't catch this man, the invasion of Europe will have to be postponed possibly for a year. In that year the balance of war could turn against us. The time may never be this right again."

Bloggs said: "Do we get told how long it is to D-Day?"

Godliman decided they were at least as entitled as he; they were going into the field, after all. "All I know is that it's probably a matter of weeks."

Parkin was thinking, "It'll be June, then."

The phone rang and Godliman picked it up.

After a moment he looked up. "Your car's here."

Bloggs and Parkin stood up.

Godliman said, "Wait a minute."

They stood by the door, looking at the professor.

He was saying, "Yes, sir. Certainly. I will. Good-bye, sir."

Bloggs could not think of anyone Godliman called Sir. He said: "Who was that?"

Godliman said, "Churchill."

"what did he have to say?" Parkin asked, awestruck.

Godliman said, "He wishes you both good luck and Godspeed."

The carriage was pitch dark. Faber thought of the jokes people made, "Take your hand off my knee. No, not you, you." The British would make jokes out of anything. Their railways were now worse than ever, but nobody complained any more because it was in a good cause. Faber preferred the dark; it was anonymous.

There had been singing, earlier on. Three soldiers in the corridor had started it, and the whole carriage had joined in. They had been through "Be Like the Kettle and Sing", "There'll Always Be an England" (followed by "Glasgow Belongs to Me" and "Land of My Fathers" for ethnic balance), and, appropriately, "Don't Get Around Much Any More."

There had been an air raid warning, and the train slowed to thirty miles an hour. They were all supposed to lie on the floor, but of course there was no room. An anonymous female voice had said, "Oh, God, I'm frightened," and a male voice, equally anonymous except that it was cockney, had said: "You're in the safest place, girl they can't 'it a moving target." Then everyone laughed and nobody was scared any more. Someone opened a suitcase and passed around a packet of dried-egg sandwiches.

One of the sailors wanted to play cards. "How can we play cards in the dark?"

"Peel the edges. All Harry's cards are marked."

The train stopped unaccountably at about 4 A.M. A cultured voice -the dried-egg-sandwich supplier, Faber thought-said, "My guess is we're outside Crewe."

"Knowing the railways, we could be anywhere from Bolton to Bournemouth," said the cockney.

The train jerked and moved off, and everyone cheered. Where, Faber wondered, was the caricature Englishman with his icy reserve and his stiff upper lip? Not here.

A few minutes later a voice in the corridor said: "Tickets, please." Faber noted the Yorkshire accent; they were in the north now. He fumbled in his pockets for his ticket.

He had the corner seat, near the door, so he could see into the corridor. The inspector was shining a flashlight onto the tickets. Faber saw the man's silhouette in the reflected light. It looked vaguely familiar.

He settled back in his seat to wait. He remembered the nightmare: "This is an Abwehr ticket" and smiled in the dark.

Then he frowned. The train stopped unaccountably; shortly afterward a ticket inspection began; the inspector's face was vaguely familiar... It might be nothing, but Faber stayed alive by worrying about things that might be nothing. He looked into the corridor again, but the man had entered a compartment.

The train stopped briefly-the station was Crewe, according to informed opinion in Faber's compartment-and moved off again.

Faber got another look at the inspector's face, and now he remembered. The boarding house in Highgate! The boy from Yorkshire who wanted to get into the Army!

Faber watched him carefully. His flashlight moved across the face of every passenger. He was not just looking at the tickets.

No, Faber told himself, don't jump to conclusions. How could they possibly have got on to him? They could not have found out which train he was on, got hold of one of the few people in the world who knew what he looked like, and got the man on the train dressed as a ticket inspector in so short a time...

Parkin, that was his name. Billy Parkin. Somehow he looked much older now. He was coming closer.

It must be a look-alike, perhaps an elder brother. This had to be a coincidence. Parkin entered the compartment next to Faber's. There was no time left.

Faber assumed the worst, and prepared to deal with it. He got up, left the compartment, and went along the corridor, picking his way over suitcases and kitbags and bodies, to the lavatory. It was vacant. He went in and locked the door.

He was only buying time: even ticket inspectors did not fail to check the toilets. He sat on the seat and wondered how to get out of this. The train had speeded up and was travelling too fast for him to jump off.

Besides, someone would see him go, and if they were really searching for him they would stop the train. "All tickets, please." Parkin was getting close again.

Faber had an idea. The coupling between the carriages was a tiny space like an air-lock, enclosed by a bellowslike cover between the cars of the train, shut off at both ends by doors because of the noise and draughts. He left the lavatory, fought his way to the end of the carriage, opened the door, and stepped into the connecting passage. He closed the door Behind him.

It was freezing cold, and the noise was terrific. Faber sat on the floor and curled up, pretending to sleep. Only a dead man could sleep here, but people did strange things on trains these days. He tried not to shiver. The door opened behind him. "Tickets, please." He ignored it. He heard the door close. "Wake up, Sleeping Beauty." The voice was unmistakable. Faber pretended to stir, then got to his feet, keeping his back to Parkin.

When he turned the stiletto was in his hand. He pushed Parkin up against the door, held the point of the knife at his throat, and said, "Be still or I'll kill you."

With his left hand he took Parkin's flashlight, and shone it into the young man's face. Parkin did not look as frightened as he ought to be. Faber said, "Well, well, Billy Parkin, who wanted to join the Army, and ended up on the railways. Still, it's a uniform."

Parkin said, "You."

"You know damn well it's me, little Billy Parkin. You were looking for me. Why?" He was doing his best to sound vicious.

"I don't know why I should be looking for you. I'm not a policeman."

Faber jerked the knife melodramatically. "Stop lying to me."

"Honest, Mr Faber. Let me go-I promise I won't tell anyone I've seen you."

Faber began to have doubts. Either Parkin was telling the truth, or he was overacting as much as Faber himself.

Parkin's body shifted, his right arm moving in the darkness. Faber grabbed the wrist in an iron grip. Parkin struggled for an instant, but Faber let the needle point of the stiletto sink a fraction of an inch into Parkin's throat, and the man was still. Faber found the pocket Parkin had bees reaching for, and pulled out a gun.

"Ticket inspectors do not go armed," he said. "Who are you with, Parkin?"

"We all carry guns now... there's a lot of crime on trains because of the dark."

Parkin was at least lying courageously and creatively. Faber decided that threats were not going to be enough to loosen his tongue.

His movement was sudden, swift, and accurate. The blade of the stiletto leaped in his fist. Its point entered a measured half inch into Parkin's left eye and came out again.

Faber's hand covered Parkin's mouth. The muffled scream of agony was drowned by the noise of the train. Parkin's hands went to his ruined eye. "Save yourself the other eye, Parkin. Who are you with?"

"Military Intelligence, oh God, please don't do it again."

"Who? Menzies? Masterman?"

"Oh, God... Godliman, Godliman."

"Godliman?" Faber knew the name, but this was no time to search his memory for details. "What have they got?"

"A picture. I picked you out from the files."

"What picture? What picture?"

"A racing team, running, with a cup, the Army."