Lee Child, one of Britain's bestselling authors, explores the phenomenal popularity of his character Jack Reacher - the basis of a new blockbuster movie starring Tom Cruise. In an insightful interview with Andrew Graham-Dixon, he reveals how being made redundant at age 40 pushed him into a life of writing and led him to New York, where he now lives. But despite the American setting of the highly successful Jack Reacher series, it is poignant elements of his childhood in Birmingham that form the basis of his fiction.