Hoping for a fresh start, a homeless teenager and his father head for San Francisco in this first novel from an author of picture hooks (The Sugaring-Off Party, p. 228, etc.). San Francisco is crowded with street people and short on employment. Admitted temporarily to a family shelter, Aaron spends his days aimlessly as his father tracks down odd jobs, sells his blood a pint at a time, and saves enough to buy a van. Off they go to the fields, becoming migrant laborers for a season--until a climactic forest fire brings near-tragedy and a change of luck: a job offer from the local fire chief. London casts his story in short, easy chapters, doesn't go for shock value (all that Maria, a young woman Aaron meets, will say about her private life is that she makes her rent ""dancing. In one of those--you know--adults-only joints.""), and ties up loose ends neatly. The focus here is as much on the hostility of police and some members of the public as on the dangers and discomforts of homelessness. Topped by the predictable happy ending, this slides down rather easily, but Aaron's desperate wish for a home may spark a response in younger readers.