'I don't know,' Helen said, and reiterated: 'I'm from the University.'

'Oh,' the woman replied, as if this was new information, 'so you're nothing to do with the Council?'

'No.'

'Some of it's obscene, isn't it?; really dirty. Makes me embarrassed to see some of the things they draw.'

Helen nodded, casting an eye at the boy in the pushchair. Kerry had decided to put his sweet in his ear for safe-keeping.

'Don't do that!' his mother told him, and leaned over to slap the child's hand. The blow, which was negligible, began the child bawling. Helen took the opportunity to return to her camera. But the woman still desired to talk. 'It's not just on the outside, neither,' she commented.

'I beg your pardon?' Helen said.

'They break into the flats when they go empty. The Council tried to board them up, but it does no good. They break in anyway. Use them as toilets, and write more filth on the walls. They light fires too. Then nobody can move back in.'

The description piqued Helen's curiosity. Would the graffiti on the inside walls be substantially different from the public displays? It was certainly worth an investigation.

'Are there any places you know of around here like that?'

'Empty flats, you mean?'

'With graffiti.'

'Just by us, there's one or two,' the woman volunteered. 'I'm in Butts' Court.'

'Maybe you could show me?' Helen asked.

The woman shrugged.

'By the way, my name's Helen Buchanan.'

'Anne-Marie,' the mother replied.

'I'd be very grateful if you could point me to one of those empty flats.'

Anne-Marie was baffled by Helen's enthusiasm, and made no attempt to disguise it, but she shrugged again and said: 'There's nothing much to see. Only more of the same stuff.'