"Dr. Rothstein's laboratory."

I said: " I'd like to speak to him."

"He's just left here, I'm afraid. Can I give him your message?"

"There's no message."

I put the receiver down.

Solly Rothstein was burning to tell me something and it was something so vital that no one must overhear. If they knew him, and knew his voice, they would know that he was on his way here now, because of the tap. And they would try to stop him. And there was nothing I could do.

The Zehlendorf district was ten kilometres from the east side of Tempelhof, so he wouldn't walk all the way. Nor would he simply take his car or a taxi from door to door; his tactics were already cautious; he would dodge about. Hopeless to start out from here and try to intercept him. Must wait here for him.

Time-check: 5.09. Ten kilometres by car or taxi through the beginning of the rush-hour: twenty minutes. Add five, because he'd start out on foot if he were taking a taxi, and pick it up some distance from base; or he'd take it from base and leave it some distance from here. He might even take a trolley or the overhead but it was unlikely because he was impatient. He would be here between twenty minutes and half an hour from now. 5.29 to 5.39.

I didn't phone the laboratory again to ask if he normally used a car or taxis because they would tap me, and if they'd no plans for Solly at this moment I didn't want to suggest they should make any. If I were wrong, nothing would happen. If I were right, they would be doing all they could to reach him along his route. A car would come into his mirror and stay there, waiting for the chance; or a man would open the door of his taxi and climb in while it was held at the lights; or someone would cross the road and fall in behind him along the pavement.

5.14. Nothing to do.

I left my room and went along the corridor until I found a door open. The room was empty. The curtains were filmy but opaque enough by winter daylight. Five minutes' gradual movement and the hem was parted an inch from the window-frame and I checked the apartments across the street. The window four up and seven along was open, a dark square. I let the curtain fall and came away.

At 5.23 I went down and wandered around the main reception-lounge, keeping within sight of the switchboard so that the girl would recognise me and know I wasn't in my room, because Solly might conceivably phone again if he sensed he was being followed.

At 5.27 I went through the revolving doors and down the steps and crossed the road and stood well back in the doorway of the apartments, so that my head would have to turn only about a hundred and twenty degrees instead of one-eighty to keep each end of the street under alternate observation. He might come from either direction.

My breath floated grey on the cold air. Tyres hissed along wet tarmac. Two men came down the steps of the Prinz Johan and turned west side by side. Time 5.34. Didn't matter now, just have to wait and go on waiting. Cold. Cold outside and cold inside. Carelessness, bloody carelessness. Getting old.

A Borgward pulled in at the kerb and I had to shift my position to keep the east end of the street under watch. Present population of street: woman and dog ten degrees left coming east, man in black overcoat ninety degrees right coming west, two girls one-double-o right catching up, hear their voices, one laughing. Two men (same two?) extreme left coming east (coming back?). Borgward away, gas acrid on the air. Shift position. Girls passing black overcoat. Man extreme right coming west. Check left, check right. Walking quickly, short, black hat. Check left, check right. Yes.

I left the doorway and walked slowly at first to keep him under scrutiny and when the distance was fifty or sixty yards and I could recognise him with certainty I quickened and took a gap in the traffic and crossed over. We were closing on each other from thirty yards and all I had in my pockets were keys but they'd have to do. Twenty yards and within calling-distance. Stop. Check. Four up and seven along – and I was running, calling his name and shouting for him to dodge. He saw me, surprised. I flung the keys full at his face and they whistled through the air but never hit him because he was staggering, toppling, as the thin crack of sound echoed across the blank stone face of the buildings.

I caught him as he fell.

"Solly," I said to him, "it was my fault." He didn't hear.

I phoned the Z-polizei within ten minutes and said:

"You may like to get some men along to 193 Potsdamerstrasse, top floor, a laboratory. Make sure they're armed. I'm expecting some trouble there."

I recognised the captain's voice. He said:

"We've just sent a squad in. There was a call from there not long ago reporting a raid. Papers were taken."

"Get them back if you can. Listen, please: I have an address for you. Concierge's office, main entrance, the Mariengarten building, middle of the Schonerlinde-strasse, Tempelhof." He was repeating, so that a clerk could get it down. "The laboratory is run by Dr. Solomon Rothstein. He's just been shot dead in the street outside the Mariengarten building and I've brought him in here. Shot was fired from a window of the Schonerpalast on the other side of the street, fourth floor, seven windows from the east end of the block. Telescopic rifle. Ambulance already laid on for Dr. Rothstein. I shall be here when you come."

I left the porter in charge of the body and pushed through the crowd in the entrance, going across to the Schonerpalast and hurrying the concierge into the lift, saying "The Kriminalpolizei will be here in a few minutes and no one must go into the room until they arrive." He asked me what had happened and I just told him it was a homicide case. "I want the seventh window from the end of this corridor."

It was apartment 303. The door pushed open easily and I didn't even bother to check the hingeside gap for anyone standing behind it. The marksman would have been out of this room and this building before I had carried the body into the Mariengarten. There was nothing unusual about the room except that it was cold in contrast to the corridor. The concierge went to shut the window and I stopped him. "Don't touch anything please." There was some greaseproof paper, empty, with the word Lunchpak printed on it, on the floor by the window. An ashtray was heaped with cigarette-butts.

I looked down across the street. The ambulance was just pulling up. Two men cleared a way through the small crowd of people, one of them carrying a rolled stretcher. I told the concierge to lock the door of the room and wait for the police to come.

It was necessary for me to keep active and not think about Solly. That would come later; remorse – worse, guilt – would set in like a rot and I would never be wholly free of it. I had never counted the men I had killed during the last thirty years, nor had the thought of their dying ever concerned me. Most of them had been Nazis during the short period of the war; the rest had died because they were in the act of attempting to kill me. They had all been enemies. Solly had been a friend and I'd killed him by carelessness.

Before the setting-in of permanent remorse there would be this immediate phase of self-fury to combat, and action was the sole anodyne.

A black Mercedes was stationed behind the ambulance when I went down and crossed the road but I turned left along the pavement and went into the yard of the hotel and got out the Volkswagen, heading due west and reaching the Potsdamer-strasse inside fifteen minutes by taking the new perimeter road round the airport and playing the lights on the amber most of the way.

The captain was still at the laboratory. He had followed up the emergency-squad after my call to him. He was the Z-officer who'd been with me on the Rauschnig-Schrader-Foegl operation. His name was Stettner. He said: