Laurence Schofield's world was torn apart when his teenage daughter vanished. No trace was ever found. But six years later, a TV crew filming in London records a few seconds' footage of a girl who just could be her. Schofield heads for the capital. But this isn't the London of the tourist brochures: it's the Tinderbox, an area of dangerous dereliction where the homeless have created an alternative society with its own rules.