The Chase (a.k.a. Pursuit) by Richard Unekis (Gollancz, 1963): the Original Novel (a Lewes Book Bargain), Basis for the 1974 Movie Dirty Mary, Crazy Larry

NB: Featured as one of this week's Friday's Forgotten Books.

Into the second week of posts on books which begat perhaps more famous films we go. And this next novel is an obscure crime fiction work originally published in 1962 and adapted for the screen in 1974 – although not especially faithfully...

This is the UK hardback first edition of Richard Unekis's The Chase, published by Gollancz in 1963, originally published in the States by Walker in 1962, and subsequently published under the title Pursuit by Signet in 1964. I bought this copy in the Lewes Antiques Centre a couple of years ago, with no real notion of what it was, other than what I could glean from the dust jacket flap blurb. It was only later I realised it was the basis for the 1974 cult road movie Dirty Mary, Crazy Larry, directed by John Hough and starring Peter Fonda, Susan George, Adam Roarke and Vic Morrow.

There are, however, significant differences twixt book and film, not the least of which being that in the original novel, there's no "Dirty Mary". The film begins much as the novel does, with NASCAR hopefuls Larry Rayder (Fonda) and Deke Sommers (Roarke) enacting a daring daylight supermarket heist by holding the store manager's wife and child hostage – although in the book Rayder's first name is Floyd while Sommers is simply called Grozzo, and both are ex-cons rather than prospective racing drivers. But a major change comes with the addition of Mary Coombs (Susan George), Rayder's one-night-stand, who hitches a ride with the heisters: Mary is an invention of the movie, and doesn't appear in the novel. Moreover, the approaches and aims of the book and the film are quite different, as Richard Unekis had a very specific concept in mind with The Chase.

The Wikipedia page for the adaptation of Dirty Mary, Crazy Larry boasts a pretty detailed account of how the various changes came about, so I shan't dwell on them here. But it's also unfairly dismissive of Unekis's novel, calling it "an out of date book with little literary value except for a car chase". In fact The Chase has more going for it than that. Admittedly there's not much in the way of character development, but then neither is there in the movie; Unekis is more interested in exploring applied mathematics and probabilities, in particular how to "maximise or minimize the chances for interception" – in other words, Game Theory.

In making their escape, Rayder and Grozzo utilise the gravel roads "running straight by the compass in all four directions" to the south of Chicago. "From the air," Unekis notes at the novel's outset, these roads "make the countryside look like a giant checkerboard, running perfectly flat all the way to the horizon. There are so many roads that, in any manhunt, it is impossible to block them all. The state police do not even try. They just block the major highways—and hope." Enter Superintendant Franklin, the man heading up the hunt for Rayder and Grozzo. Instead of following the standard protocol, Franklin draws on his naval background plotting positions of submarines in order to work out where Rayder and Grozzo are heading, and what their most likely route will be. The result is a tense, clammily exciting game of cat-and-mouse, as Franklin deducts that the pair are headed for Chicago and directs the police cars at his disposal to cut them off, and Rayder and Grozzo barrel along at terrifying speeds on the dangerous gravel roads, a couple of times escaping seemingly certain death by the skin of their teeth.

Aside from a 2009 obituary, there's little in the way of information about Richard Unekis available online; The Chase was his only published novel, and fell out of print decades ago – there are only around twenty copies of the book in any edition available on AbeBooks (among them a single Gollancz first). But the Edgar Awards committee for 1962 thought highly enough of The Chase to shortlist it for the Best First Mystery Novel prize, and to my mind it deserves rescuing from obscurity: it's not perfect by any means, but in its intriguing deployment of mathematics in a high speed pursuit scenario, it displays enough ambition to make it worth a second look.

And I've another Gollancz first edition for the next post in this run, this time a hip, dialogue-heavy '70s crime fiction novel which begat a gloriously daft '80s action comedy...