Max is released from prison and returns to London to find that his wife has emigrated and that his son is missing. He leaves London and embarks on his narrowboat Harmony. He takes up with a young woman, Andrea, and sorts out a demanding drug dealer for a former nurse who has become addicted. He gives her the drug dealer's money so she can book herself into a clinic.

Max's quest leads him to a village in Wales, where he immediately comes under suspicion when a local girl goes missing.