Jim Maliano watched from the living-room doorway as the motley crowd walked down the dark hall. When Maureen came past him he reached out and squeezed her shoulder gently. His small gesture of empathy touched Maureen unreasonably and she vowed not to forget it.

The rest of it was a bit of a blur. She remembered Winnie crying loudly and a small crowd parting outside the close to let her through. The red-haired man got into the driver's seat of a blue Ford and the policewoman helped Maureen into the backseat, climbing in next to her. He asked if she had been cautioned. She said she had but she wasn't really listening. He recited it for her. Within minutes they were in Stewart Street police station.

It was just round the corner from her house but Maureen hadn't paid much attention to it before. The three-story concrete building sat on the edge of an industrial estate and was fronted with reflective glass. It looked more like an office block than a police station. They drove round to the back and pulled into a small car park. It was surrounded by a high wall topped with spiraled razor wire. Looking up at the back of the building from the car park, she could see small, mean, barred windows.

The red-haired man helped her out of the car, holding on to her elbow longer than he need have. She must look a bit wobbly. "Now, don't you worry," he said. "That's the worst bit over. We're only going to talk to you."

But Maureen wasn't thinking about that. She just wanted to see Liam.

Maureen was the youngest of the four of them. They all bore a striking family resemblance: dark brown hair, square jaws and fat button noses. Their build was the same too: they were all short and thin. When they were children, people often mistook Liam and Maureen for twins: they had been born ten months apart, both had pale blue eyes and they spent so much time together they adopted all of the same mannerisms. When they hit puberty Liam refused to hang about with Maureen. She didn't understand: she followed him around like a little dog until he threatened to beat her up and stopped talking to her. Their resemblance gradually faded.

Marie was the eldest. She moved to London in the early eighties to get away from her mum's drinking, settled there and became one of Mrs. Thatcher's starry-eyed children. She got a job in a bank and worked her way up. At first the change in her seemed superficial: she began to define all her friends by how big their mortgage was and what kind of car they drove. It took a while for them to realize that Marie was deep down different. They didn't talk about it. They could talk about Winnie's alcoholism, about Maureen's mental-health problems, and to a lesser extent about Liam dealing drugs, but they couldn't talk about Marie being a Thatcherite. There was nothing kind to be said about that. Maureen had always assumed that Marie was a socialist because she was kind. The final break between them came the last time Marie was home for a visit. They were talking about homelessness and Maureen ruined the dinner for everybody by losing the place and shouting "Get a fucking value system!" at her sister.

It happened six months before Maureen was taken to hospital, but the way Marie told it there was only a matter of weeks between one incident and the other. And that explained it. Maureen was mental and Marie forgave her.

Marie was married to Robert, another banker, who worked in the City. They had been married on the quiet in the Chelsea Register Office two years before but Robert had never found the time to come to Glasgow and pay his respects to her family. It was a shame because now he couldn't afford to: he had become a Lloyd's Name at just the wrong time, on just the wrong syndicate, and they were living in a bedsit in Bromley.

Una's husband, Alistair, was an integral part of the family. He was a plumber and couldn't believe his luck when Una agreed to marry him. He was a quiet, honorable man and, to Una's everlasting joy, had proved himself eminently malleable. She began by changing the way he dressed, then moved on to his accent, and at the moment she was trying to change his career.

Una was a civil engineer and made a right few quid. She scheduled beginning a family for 1995 and had virtually booked her maternity leave but she didn't get pregnant. She put a brave face on it but recently she had confided in them all, individually and in confidence, that she was getting desperate. Maureen went with her to the clinic when she had the preliminary tests. It turned out that Alistair's sperm count was a bit low and he was put on a course of medication. Una was happy and Alistair was if she was.

When it came time for Liam to go to secondary school, Michael, their father, had lost his job as a journalist because of his drinking, quite a feat in those days. They couldn't afford to send Liam to the private school Marie and Una had been to so he was sent to Hill-head Comprehensive and Maureen followed him a year later. It was a good school but neither of them studied very hard.

Winnie's alcoholism progressed rapidly after Michael left them. Within four years she was married again and their new stepfather, George, became the silent partner in loud, brutal arguments. Despite the atmosphere in the house Liam delighted his mother by getting into Glasgow University Law School. He dropped out after six months and started selling hash to his friends on a casual basis but he discovered a talent and went professional. He bought a big house. They told Winnie he managed bands. Maureen used to nag him about security in the house but he said that if he started to worry about things like that he'd get really paranoid.

His present girlfriend, Maggie, was a bit of a mystery. She was a model, but they never saw her model anything, and a singer, but they never heard her sing either. She was very pretty and had the roundest arse Maureen had ever seen. She didn't seem to have any friends of her own. Poor Maggie had a lot to live up to: Lynn, Liam's first and last girlfriend, was a doctor's receptionist and as rough as a badger's arse but such great crack even Winnie's snobbishness dissipated when Lynn told a story.

Maureen did well at school and went straight to Glasgow University to study history of art. She was in her final year when she began to think she was schizophrenic. The night terrors she had always suffered from got progressively worse and she started having waking flashbacks. They were mild at first but escalated in frequency and severity. Because she didn't know what she was flashing back to, she thought they were random delusions. In her more lucid moments she realized something was very wrong. She had never done acid so that wasn't it. She began to read about mental illness and found that she was in the right age group for her first schizophrenic attack. She wasn't very surprised: like many people from unhappy families she'd never assumed the future would hold anything too thrilling. She told no one, got the job at the Apollo Theatre and bought the tiny flat in Garnethill so that when she fell down the big black hole into the hands of the social services they wouldn't make her live with Winnie.

It took a year and a half of patient panic for the breakdown to come.

She was sitting upstairs on a bus. A fat man sitting behind her was breathing mucousally in her ear. The noise got louder, closer, more rasping, until it was deafening. She waited for him to hit her, a fisted slap on the side of her head. When it didn't happen she screamed for a bit and threw up. The driver came to see what was wrong and found her sobbing and trying to wipe up the mess with a single tissue. He told her to leave it. She ran off the bus. None of the other passengers came after her.