Cassie Schofield, aged 15, goes missing from her comfortable, middle-class home in Birmingham.

 

Six years later, her grainy image is seen in the background of a documentary about homelessness. Her father, Laurence Schofield sets off to London to find her and bring her home.

 

Helped initially by the producer of the programme and later by a young man, Jonah, Schofield is thrown into the underworld that exists in The Tinderbox.