The party was one of the most successful Laing had attended. Unlike the majority of parties in the high-rise, at which well-bred guests stood about exchanging professional small-talk before excusing themselves, this one had real buoyancy, an atmosphere of true excitement. Within half an hour almost all the women were drunk, a yardstick Laing had long used to measure the success of a party.

When he complimented Talbot the psychiatrist was non-committal. "There's a quickening pulse in the air, all right, but has it anything to do with good humour or fellow-feeling? Rather the opposite, I'd guess."

"You're not concerned?"

"For some reason, less than I should be-but that's true of us all."

These agreeably expressed remarks cautioned Laing. Listening to the animated conversations around him, he was struck by the full extent of the antagonisms being expressed, the hostility directed at people who lived in other sections of the high-rise. The malicious humour, the eagerness to believe any piece of gossip and any tall story about the shiftlessness of the lower-floor tenants, or the arrogance of the upper-floor, had all the intensity of racial prejudice.

But as Talbot had pointed out, Laing found himself unworried by all this. He even took a certain crude pleasure in joining in the gossip, and in watching the usually circumspect Charlotte Melville put down several more than two drinks too many. At least it was a means by which they could reach each other.

However, as the party broke up a small but unpleasant episode took place outside the elevator doors in the 27th-floor lobby. Although it was after ten o'clock, the entire building was alive with noise. Residents were barging in and out of each other's apartments, shouting down the staircases like children refusing to go to bed. Confused by the endless button-punching, the elevators had come to a halt, and gangs of impatient passengers packed the lobbies. Although their next destination, a party given by a lexicographer on the 26th floor, was only one storey below them, everyone leaving Talbot's party was determined not to use the stairs. Even Charlotte, face flushed and tottering happily on Laing's arm, joined in the wild surge across the elevator lobby and drummed on the doors with her strong fists.

When at last an elevator arrived, the doors opened to reveal a solitary passenger, a thin-shouldered and neurasthenic young masseuse who lived with her mother on the 5th floor. Laing immediately recognized her as one of the "vagrants", of whom there were many in the high-rise, bored apartment-bound housewives and stay-at-home adult daughters who spent a large part of their time riding the elevators and wandering the long corridors of the vast building, migrating endlessly in search of change or excitement.

Alarmed by the drunken crowd reeling towards her, the young woman snapped out of her reverie and pressed a button at random. A derisory hoot went up from the swaying guests. Within seconds she was pulled from the elevator and put through a mock-playful grilling. A statistician's over-excited wife shouted at the hapless girl in a shrill voice, pushed a strong arm through the front rank of interrogators and slapped her face.

Pulling himself away from Charlotte, Laing stepped forward. The crowd's mood was unpleasant but difficult to take seriously. His neighbours were like a group of unrehearsed extras playing a lynch scene.

"Come on-I'll see you to the stairs." Holding the young woman by her thin shoulders, he tried to steer her towards the door, but there was a chorus of sceptical shouts. The women among the guests pushed aside their husbands and began to punch the girl on the arms and chest.

Giving up, Laing stood to one side. He watched as the shocked young woman stumbled into the mouth of this eager gauntlet and was pummelled through a circuit of fists before she was allowed to disappear into the stairwell. His reflex of chivalry and good sense had been no match for this posse of middle-aged avenging angels. Uneasily, he thought: careful, Laing, or some stockbroker's wife will un-man you as expertly as she de-stones a pair of avocados.

The night passed noisily, with constant movement through the corridors, the sounds of shouts and breaking glass in the elevator shafts, the blare of music falling across the dark air.