"What," Graham said contemptuously, annoyed, "that tall bloke with the bleached hair in first year? He's thick,"

"Hmm, well," Slater said, bobbing his head in an arc - a gesture somewhere between a nod and a shake - "thick set, certainly, and not awfully bright, but God those shoulders. That waist, those hips! I don't care about his head; from the neck down he's a genius,"

"Idiot," said Graham.

"Trouble is," Slater mused, "he either doesn't realise what I'm up to, or he doesn't care. And he has this awful friend, called Claude... I keep telling him how earthy I think he is, but he hasn't got it yet. Now he really is thick. I asked him what he thought of Magritte the other day, and he thought I was talking about some girl in first year. And I can't get him away from Roger. I shall die if he's gay. I mean if he got there first. I'm sure Roger isn't really stupid, it's just his friend who's infectious,"

"Ha ha," Graham said. He always felt slightly uncomfortable when Slater talked about being gay, though his friend was rarely specific, and Graham was hardly ever directly involved - he had, for example, only ever met one of Slater's (supposedly many) lovers, at least as far as he knew.

"Do you know," Slater said, suddenly brightening, as they crossed John Street, "I've had this really good idea."

Graham gritted his teeth: "Well, what is it this time? Another new religion, or just a way of making lots of money? Or both?"

"This is a literary idea."

"If it's The Sands of Love, I've already heard it."

That was a great plot. No, it isn't romantic fiction this time." They stopped at the corner of Gray's Inn Road, waiting for the lights to change. A couple of punks on the far side, also waiting to cross, were pointing at the oblivious Slater and laughing. Graham looked up at the skies and sighed.

"Imagine, if you will," Slater said dramatically, sweeping his arms out wide, "a -"

"Keep it short," Graham told him.

Slater looked hurt. "It's a sort of Byzantine future, a degenerate technocratic empire with -"

"Oh, not science fiction again."

"Well, no, it's not really, smart-ass," Slater said. "It's a... fable. I could make it a fairy-tale instead, if I wanted to. Anyway. It's the capital of the empire; a courtier starts a liaison with one of the princesses; the demands she and the Emperor make on his time get to be too much, so he secretly has an android made to impersonate him at the endless court rituals and boring receptions; nobody notices. Later he has the android's brain upgraded so it can cope with hunting expeditions and personal meetings, even Cabinet discussions with the Emperor present, all so that he can spend more time dallying with the princess. But he gets killed in some over-energetic love-play. The android continues to fulfil all its courtly duties and even becomes a trusted confidant of the Emperor, and the princess discovers it actually makes a better lover than the original. The android can fit in all its commitments because it never has to sleep. But it develops a conscience, and has to tell the Emperor the truth. The Emperor smiles, opens up an inspection panel in his chest and says, 'Well, by a funny coincidence...' End of story. Pretty good, eh? What do you think?"

Graham took a deep breath, thought, then said. "These pilots: so they could disguise their boots. What about their uniforms?" He frowned seriously.

Slater stopped, a look of horror and confusion on his face. "What?" he said, aghast.

Suddenly Graham realised - with a small, disquieting feeling in his stomach - that they were standing right outside a place which always made him feel apprehensive.

It was only a small picture-framing shop which sold prints and posters and more-tasteful-than-average lampshades, but it was the name which held unpleasant associations for Graham: Stocks. That name chilled him.

Stock was his rival, the great threat, the cloud hanging over him and Sara. Stock the biker, the macho black-leathered never-properly-seen image of Nemesis. (He had looked up the name in the London telephone directory; there were one-and-a-half columns of them; enough for quite a few coincidences, even in a city of six-and-a-half million people.)

Slater was saying, "- to do with it?"

"It just occurred to me," Graham said defensively. He wished now he hadn't decided to tease Slater.

"You haven't listened to a word I've said," Slater gasped. Graham nodded to indicate they should keep on walking.

"Of course I have," he said. They passed Terry's fruitstall next, with its smell of fresh strawberries, then a chemist's. They were at the junction of Clerkenwell Road and Rosebery Avenue. By the side of Gray's Inn Buildings, which led on up the Avenue, some tall green wooden hoardings jutted out over part of the street and pavement, shielding some roadworks. Graham and Slater walked down the narrow alley formed by the seedy, decaying stonework and the painted wood; Graham saw the grimy glass of cracked windows; fading political posters flapped in a slight breeze.

"But don't you think it's a laugh?" Slater said, trying to edge round Graham to peer into his face. Graham avoided his friend's eyes. He wondered if Slater intended to walk the whole way with him, or whether he was only going as far as the Air Gallery, now only just across the street, where he sometimes went in the afternoons. Graham didn't mind Slater knowing about Sara - he had introduced them to each other, after all - but he wanted to keep this day private. Besides, he got embarrassed at the stares people gave Slater, even if Slater himself didn't seem to notice. The least he could do, Graham thought, was take off that ridiculous tartan cap.

"It's... all right," he conceded as they came out from between the decaying buildings and the green hoardings, "but..." he smiled and looked at Slater, "don't give up your day job."

"And don't you quote my own lines back at me, you young pup!"

"Okay," Graham said, looking at Slater again. "Stick to ceramics."

"You make me sound like a glaze."

"That's your expression."

"Oh-ho," Slater said, "well, touche, or toushe, anyway." He stopped by the pedestrian crossing which led over Rosebery Avenue to the square, red-brick building of the Air Gallery. Graham turned to face him. "But don't you like the latest scenario?"

"Well," Graham said slowly, deciding he had better say something nice, "it's good, but perhaps it needs a little work."

"Huh," Slater said, stepping back and rolling his eyes. He came forward again, eyes narrowed, pushing his face close to Graham's so that the younger man shrank back just a little." 'A little work', eh? Well, bang goes your commission from the National Portrait Gallery when I'm famous."

"Are you going over there?" Graham indicated the far side of the road.

Slater slouched a little and nodded, looking over the road to the gallery.

"I suppose so. You're trying to get rid of me, aren't you?"

"No I'm not."

"Yes you are. You've been hurrying me all the way."

"No, I wasn't," Graham protested. "It's just that you walk slowly."

"I was talking to you."

"Well, I can walk and listen at the same time."

"Oh, wow, the Gerry Ford of the Art School. Anyway, not to worry; I bet I know where you're off to, hmm?"

"Oh?" Graham said, trying to look innocent.

"Yes, I can tell," Slater said. "Stop trying to look so damn nonchalant." A smile appeared on his face like oil surfacing on still water. "You've got the hots for our Sara, haven't you?"

"Oh, intensely," Graham said, trying to over-play it; but he could see Slater wasn't taken in. But it wasn't like that; it wasn't that crude, or even if it was it shouldn't be talked of in such a way; not now, not yet.

They aren't worth it, kid," Slater said, shaking his head sadly and wisely. "She'll let you down. Later if not now. They always do."