The Dazzle, By Robert Hudson. Jonathan Cape, £16.99

Set mainly in the waters off the Yorkshire coast, the second novel from the author of The Kilburn Social Club is a cocktail-age yarn compounded from equal parts of sex, drugs and big-game fishing, topped with a dash of espionage. The giant tuna aspect may seem a bit unlikely for Scarborough, but such creatures were the prey of sportsmen in the Thirties.

In an afterword, the author says he "thought long and hard about whether to use real names". He succumbed, though evidently felt no obligation to stick to reality. One major figure is Zane Grey, the Western writer, who was indeed obsessed with big-game fishing but, as Hudson admits, "never visited England". Another is Martha Gellhorn, who floated round Europe before she met Ernest Hemingway in 1936.

None of this matters if the story works – and it does, kind of. You keep turning the pages, even if not entirely sure what's going on. The Dazzle might apply to the dizzying torrent of events and walk-on parts, though it is the name of a massive pleasure boat belonging to the morally ambiguous Johnny Fastolf, Earl of Caister (an invention). The vessel's livery of "willynillacious stripes" derives from Hudson's in-depth research of the Thirties.

Even if the dialogue lacks the brittle wit of Waugh, Hudson handles his ambitious tale confidently with a good feel for period. The main problem with the narrative is that much is told in epistolary form. After a day spent reeling in giant fish, the 26-year-old Gellhorn apparently liked nothing better than writing a 12-page letter. The device becomes irksome.

The characters couple ceaselessly but since this is either described in code (Grey: "Expect kifoozling will lead to kamibbling") or not at all, Hudson has little to fear from the Bad Sex award. "Scarborough was mostly… as I portray it during the tunny-craze of the early Thirties," he insists, though there is little about onshore life. Hudson's description of the setting – "Scarborough was grey. The mist was rising. It was chilly" – would appear to be one of the real bits.