He knew where the vagrants lived, in which dis-used garages they slept. He recognized some from the pitches where they begged in the underpass at the Elephant and Castle.

'You'll know this yourself, Malachy. You're in the underpass and we'll say that four hundred people pass you in an hour, four thousand in a ten-hour begging shift, and fifty people drop a pound coin in your cap in the ten hours and think it's for dog food, or for your cup of tea. Fifty pounds in a day, that's good work, and good people have massaged their consciences as they hurry by. And you'll know that dossers empty the cap so often because it's bad for trade if people see what's actually given them. It's all for drugs, and the dog goes hungry.'

Ivanhoe Manners had walked him round the worst dark corners of the estate, where he was safe only because he had the massive prize-fighter build of the social worker with him, where the ceiling lights of the inner tunnels were smashed, where the one-time shopping arcades were wrecked, scorched – where the vagrants hunted.

'They need wraps of "brown". They have to jack up at least every twenty-four hours. You know that, you've seen it when you were under the cardboard.

They're scum when they're on heroin. The brown destroys them. They'll steal from their only friend to get the hit, think nothing of stealing from family. They inject, and they chuck the syringes away even when there's a council-provided needle exchange – and kids find them. They got hepatitis A or B or C. They got tuberculosis, they're going to get thrombosis. They thieve – anything they can sell on, but best is a purse or a wallet. The cops all wear stab-proof vests because a used needle is a weapon for the vagrants. They are dangerous, and don't ever forget it, and you go carefully when it's dark on the Amersham.'

Back in the autumn, Ivanhoe Manners had walked him by the shoebox-shaped flat-roofed public toilets.