Jack Reacher appeals to the Walter Mitty in us all. He’s the type of hero who stars in every schoolboy’s daydreams: a cartoonishly muscular soldier-turned-sleuth who beats up the bad guys, gets the girl and cracks the case with almost insolent ease.

The grown-up reader, however, envies something else: his freedom. Reacher lives a life utterly devoid of responsibility. No boss, no mortgage, no bills, no family, in fact no ties or burdens of any kind. Instead he spends his days roaming America, heading wherever the mood takes him, and effortlessly dispatching every thug, crook and cartel foolish enough to get in his way. His fans are more than just readers. We’re voyeurs.

We know we could never live a life like Reacher’s. But we love to watch, from a safe distance, as he lives it on our behalf. Reacher’s creator, Lee Child, appeals to our inner Mitty, too, albeit in a rather different way. To begin with he was plain Jim Grant: born in Coventry, raised in Birmingham, and working in a comfortable but dull-sounding job at Granada TV, pushing the buttons that made the ads come on.

Then, in 1995, at the age of 40, his position was made redundant. The scrapheap beckoned. But instead he popped down to WH Smith, bought a pencil and some paper, and relaunched himself as an American thriller writer. He’d never written a word of fiction before. Yet in next to no time, he was one of the most successful authors on Earth. Jim Grant’s life was over. Now Lee Child’s began.

The Reacher Guy, by Heather Martin, is the first-ever biography of him. Written with his cooperation, it covers both his lives in extensive detail. In the early chapters we hear a lot about his unhappy relationship with his parents. According to Grant/Child, he was "totally unwanted". He can’t remember "a single occasion when he’d had fun with his father", while he got on so badly with his mother ("mean", "malicious", "a monster of martyrdom") that he didn’t attend her funeral. Anyway, he already had other plans that day: "Why should I put them off, for a dead woman I didn’t even like?"

At school he had the reputation of being tough. On his first day at grammar school a boy pushed him against a locker. He retaliated by putting the boy in hospital, thus earning himself the nickname Grievous, as in grievous bodily harm.

The biography contains quite a few stories that are vivid and entertaining. It’s hard to avoid the suspicion, though, that some of them may not be entirely true. According to Grant/Child, at the age of just three he knocked out another boy’s teeth for pushing his brother off his tricycle ("I totally laid the guy out"). Some of his more colourful recollections are called into doubt by other interviewees. Former schoolmates "laughed at the idea Lee had grown up in a rough area", refuse to believe that he "always had a knife in my pocket", and describe as "complete cobblers" the claim that he "never saw a tree until he was 12".

Similarly disputed is his boast that, on only his third day as a backroom button-pusher at Granada, he enjoyed a picnic lunch with Alec Guinness, John Gielgud, Ralph Richardson and Laurence Olivier.

So is Grant/Child a bit of a Walter Mitty himself? Unlikely. Friends suggest he’s just keeping his audience (and himself) entertained. They want great stories, so he gives them great stories. "There’s Jim Grant, and there’s Lee Child, who I don’t know at all," says a former schoolmate. "He’s got these two personas."

The Reacher Guy by Heather Martin is available on amazon.com.

The Sunday Telegraph

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