‘A couple of years ago, when I was in the closing stages of working on my last novel, Umbrella, I began casting around for a new subject for the next one. I greatly admire WG Sebald’s The Emigrants, which tells the stories of six refugees from the Nazis without heavy-handedly describing the mechanics of the persecution that the regime visited on Jews, gay people and the politically suspect. Following this pattern, I conceived of writing a novel about some of the more interesting characters I had known during my two decades in the netherworld of drug addiction. I would fictionalise their stories, of course, but more importantly, I would never mention, or otherwise allude to, the reasons why these people lost jobs, experienced relationship-breakdown, moved abroad, and went to hospital or jail. Their addiction would remain a strange sort of absence, deforming the course of their lives but never emerging into the full light of day. My working rubric for the novel was “Jaws without the shark”.

‘I began by interviewing the woman with whom I’d begun using heroin in the late 1970s – she has, thankfully, long since cleaned up from the drug, and has a sharp and incisive angle on the soft, psychic underbelly that insulated her from the sordid realities of her active addiction. At the same time, I read Peter Benchley’s Jaws and watched Steven Spielberg’s film adaptation of the novel. I’m not altogether sure why I did this, beyond a background suspicion that I might find something usable in this material. In the event, what struck me hard was a discrepancy between the film’s script (which Benchley himself worked on), and the text of the novel.

‘In the film, an important scene takes place when Quint, the Ahab-like, obsessive shark-hunter, and Hooper, the cuddly marine biologist and shark expert, face off in the lurching cabin of Quint’s fishing boat, the Orca. Intent on out-machismoing each other, the two engage in an unusual duel that consists of comparing their shark-inflicted scars. Quint reveals that he was a sailor on board the USS Indianapolis when it was sunk by a Japanese submarine in the last days of the second world war in the Pacific. Hooper knows all about the Indianapolis: the 900-odd shipwrecked survivors, cast adrift in the ocean between Guam and Leyte as they floated on inadequate life rafts, or paddled through the heaving swell in water-logged life jackets, were the victims of the worst shark attack ever recorded. Due to some communications snafu it took three days for rescuers to arrive, and by then there were 321 survivors – one of whom was Quint.’

Read the rest of Will’s account of how and why he wrote his new novel, Shark (published by Penguin), at the Guardian here.