'What's he doing? He's not to do that. Stop him.'

If she was worried, said Smiley, she should ring Lacon on the basement phone. Millie McCraig didn't stir, but two red bruises had appeared on her leathery cheeks and she was snapping her fingers in anger. With a small screwdriver Guillam had cautiously removed the screws from either side of the plastic panel, and was peering at the wiring behind. Now, very carefully, he turned the end switch upside down, twisting it on its wires, then screwed the plate back in position, leaving the remaining switches undisturbed.

'We'll just try it,' said Guillam, and while Smiley went upstairs to check the tape deck, Guillam sang 'Old Man River' in a low Paul Robeson growl.

'Thank you,' said Smiley with a shudder, coming down again, 'that's more than enough.'

Millie had gone to the basement to ring Lacon. Quietly, Smiley set the stage. He put the telephone beside an armchair in the drawing room, then cleared his line of retreat to the scullery. He fetched two bottles of milk from the Coca-Cola ice-box in the kitchen and placed them on the doorstep to signify, in the eclectic language of Millie McCraig, that you may come in and all's well. He removed his shoes and left them in the scullery, and having put out all the lights, took up his post in the armchair just as Mendel made his connecting call.

On the canal towpath, meanwhile, Guillam had resumed his vigil of the house. The footpath is closed to the public one hour before dark: after that it can be anything from a trysting place for lovers to a haven for down-and-outs; both, for different reasons, are attracted by the darkness of the bridges. That cold night Guillam saw neither. Occasionally an empty train raced past, leaving a still greater emptiness behind. His nerves were so taut, his expectations so varied, that for a moment he saw the whole architecture of that night in apocalyptic terms: the signals on the railway bridge turned to gallows, the Victorian warehouses to gigantic prisons, their windows barred and arched against the misty sky. Closer at hand, the ripple of rats and the stink of still water. Then the drawing room lights went out; the house stood in darkness except for the chinks of yellow to either side of Millie's basement window. From the scullery a pin of light winked at him down the unkempt garden. Taking a pen torch from his pocket he slipped out the silver hood, sighted it with shaking fingers at the point from which the light had come, and signalled back. From now on they could only wait.

Tarr tossed the incoming telegram back to Ben, together with the one-time pad from the safe.

'Come on,' he said, 'earn your pay. Unbutton it.'

'It's personal for you,' Ben objected. 'Look. "Personal from Alleline decypher yourself." I'm not allowed to touch it. It's the tops.'

'Do as he asks, Ben,' said Mackelvore, watching Tarr.

For ten minutes no word passed between the three men. Tarr was standing across the room from them, very nervous from the waiting. He had jammed the gun in his waistband, butt inward to the groin. His jacket lay over a chair. The sweat had stuck his shirt to his back all the way down. Ben was using a ruler to read off the number groups, then carefully writing his findings on the block of graph paper before him. To concentrate he put his tongue against his teeth, and now he made a small click as he withdrew it. Putting aside his pencil, he offered Tarr the tearsheet.

'Read it aloud,' Tarr said.

Ben's voice was kindly, and a little fervent. ' "Personal for Tarr from Alleline decypher yourself. I positively require clarification and/or trade samples before meeting your request. Quote information vital to safeguarding of the Service unquote does not qualify. Let me remind you of your bad position here following your disgraceful disappearance stop urge you confide Mackelvore immediately repeat immediately stop Chief."'

Ben had not quite finished before Tarr began laughing in a strange, excited way. 'That's the way, Percy boy!' he cried. 'Yes repeat no! Know why he's stalling, Ben, darling? He's sizing up to shoot me in the bloody back! That's how he got my Russki girl. He's playing the same tune, the bastard.' He was ruffling Ben's hair, shouting at him, laughing. 'I warn you Ben: there's some damn lousy people in this outfit, so don't you trust the one of them, I'm telling you, or you'll never grow up strong!'

Alone in the darkness of the drawing room Smiley also waited, sitting in the housekeeper's uncomfortable chair, his head propped awkwardly against the earpiece of the telephone. Occasionally he would mutter something and Mendel would mutter back, most of the time they shared the silence. His mood was subdued, even a little glum. Like an actor he had a sense of approaching anti-climax before the curtain went up, a sense of great things dwindling to a small, mean end; as death itself seemed small and mean to him after the struggles of his life. He had no sense of conquest that he knew of. His thoughts, as often when he was afraid, concerned people. He had no theories or judgments in particular. He simply wondered how everyone would be affected; and he felt responsible. He thought of Jim and Sam and Max and Connie and Jerry Westerby and personal loyalties all broken; in a separate category he thought of Ann and the hopeless dislocation of their talk on the Cornish cliffs; he wondered whether there was any love between human beings that did not rest upon some sort of self- delusion; he wished he could just get up and walk out before it happened, but he couldn't. He worried, in a quite paternal way, about Guillam, and wondered how he would take the late strains of growing up. He thought again of the day he buried Control. He thought about treason and wondered whether there was mindless treason in the same way, supposedly, as there was mindless violence. It worried him that he felt so bankrupt; that whatever intellectual or philosophical precepts he clung to broke down entirely now that he was faced with the human situation.

'Anything?' he asked Mendel, into the telephone.

'A couple of drunks,' said Mendel, 'singing "See the jungle when it's wet with rain".'

'Never heard of it.'

Changing the telephone to his left side he drew the gun from the wallet pocket of his jacket, where it had already ruined the excellent silk lining. He discovered the safety catch and for a moment played with the idea that he didn't know which way was on and which way off. He snapped out the magazine and put it back, and remembered doing this hundreds of times on the trot, in the night range at Sarratt before the war; he remembered how you always shot with two hands, sir, one to hold the gun and one the magazine, sir; and how there was a piece of Circus folklore which demanded that he should lay his finger along the barrel and pull the trigger with his second. But when he tried it the sensation was ridiculous and he forgot about it.

'Just taking a walk,' he murmured, and Mendel said 'Righty ho.'

The gun still in his hand he returned to the scullery, listening for a creak in the floorboards that might give him away, but the floor must have been concrete under the tatty carpet; he could have jumped and caused not even a vibration. With his torch he signalled two short flashes, a long delay then two more. At once Guillam replied with three short.

'Back again.'

'Got you,' said Mendel.

He settled, thinking glumly of Ann: to dream the impossible dream. He put the gun in his pocket. From the canal side, the moan of a hooter. At night? Boats moving at night? Must be a car. What if Gerald has a whole emergency procedure which we know nothing about? A callbox to callbox, a car pick-up? What if Polyakov has after all a legman, a helper whom Connie never identified. He'd been through that already. This system was built to be watertight, to accommodate meetings in all contingencies. When it comes to tradecraft, Karla is a pedant.

And his fancy that he was being followed? What of that? What of the shadow he never saw, only felt, till his back seemed to tingle with the intensity of his watcher's gaze; he saw nothing, heard nothing, only felt. He was too old not to heed the warning. The creak of a stair that had not creaked before; the rustle of a shutter when no wind was blowing; the car with a different number plate but the same scratch on the offside wing; the face on the underground that you know you have seen somewhere before: for years at a time these were signs he had lived by; any one of them was reason enough to move, change towns, identities. For in that profession there is no such thing as coincidence.

'One gone,' said Mendel suddenly. 'Hullo?'

'I'm here.'

Somebody had just come out of the Circus, said Mendel. Front door but he couldn't be certain of the identification. Mackintosh and hat. Bulky and moving fast. Must have ordered a cab to the door and stepped straight into it.

'Heading north, your way.'

Smiley looked at his watch. Give him ten minutes, he thought. Give him twelve, he'll have to stop and phone Polyakov on the way. Then he thought: don't be silly, he's done that already from the Circus.

'I'm ringing off,' said Smiley.

'Cheers,' said Mendel. On the footpath, Guillam read three long flashes. The mole is on his way.

In the scullery Smiley had once more checked his thoroughfare, shoved some deck chairs aside and pinned a string to the mangle to guide him because he saw badly in the dark. The string led to the open kitchen door, the kitchen led to the drawing room and dining room both, it had the two doors side by side. The kitchen was a long room, actually an annexe to the house before the glass scullery was added. He had thought of using the dining room but it was too risky and besides from the dining room he couldn't signal to Guillam. So he waited in the scullery, feeling absurd in his stockinged feet, polishing his spectacles because the heat of his face kept misting them. It was much colder in the scullery. The drawing room was close and overheated but the scullery had these outside walls, and this glass and this concrete floor beneath the matting, which made his feet feel wet. The mole arrives first, he thought, the mole plays host: that is protocol, part of the pretence that Polyakov is Gerald's agent.

A London taxi is a flying bomb.

The comparison rose in him slowly, from deep in his unconscious memory. The clatter as it barges into the crescent, the metric tick-tick as the bass notes die. The cut-off: where has it stopped, which house, when all of us in the street are waiting in the dark, crouching under tables or clutching pieces of string, which house? Then the slam of the door, the explosive anti-climax: if you can hear it, it's not for you.

But Smiley heard it, and it was for him.