Mr Toppit, By Charles Elton

As a child, Luke Hayman (who will narrate much of Charles Elton's first novel) insouciantly picks up bees from a lavender bush and carries them across the garden "without bravery or fear". In a children's novel by his father Arthur, one a five-volume series that will sell in millions and lodge in the hearts of fans, a character called Luke Hayseed bears bees across a garden as a test of mettle or rite of passage – one later cited as an inspiration by survivors of an airline hijack. "They were my bees," laments the adult Luke, "and I do not remember offering them up to the world."

Luke the person is not Luke the character. Like his far more troubled elder sister, Rachel, he must still live with a past "ransacked" and "vandalised" by devotees of the "Hayseed Chronicles". These books' afterlife as a cult worshipped across continents locks the Hayman family into "a theme park from which we would never escape".

Their father's accidental death before the Hayseeds take wing – crushed by a concrete-mixer on a Soho street in the royal-wedding summer of 1981 – only tightens their golden handcuffs. In particular, the enigma of Mr Toppit will linger forever. This "unseen presence", with "his need to be obeyed", skulks as the vengeful divinity of the "Darkwood" until, at the last book's close, he comes out of the shadows "not for you, not for me, but for all of us".

As his pitch-perfect pastiche of the genre shows, Elton understands that an eerie undergrowth of horror and longing flourishes in many of the English children's classics. Curious, then, that this immensely fluent and confident debut conjures up the magic of the form only to dispel it. This is a work of disenchantment. It begins in mystery but swiftly turns to the bruised, rueful comedy of family and social manners. Woodland terrors dissolve into the light – indeed, the glaring Californian light – of common day.

Luke's plight has a well-known real-world parallel: the fate of Christopher Robin Milne, who wrote three memoirs about suffering in the shadow of Winnie the Pooh. Also looking back in bewilderment, Luke carries most of this story. We learn about Arthur's disappointed life as a screenwriter and director amid the shabby bohemianism of postwar British films; the inherited Dorset house and woods where the books unfold in the 1970s; Luke's capricious but commanding mother, Martha (Arthur and Martha: already a fairy-tale couple); and the later Hayseed mania – from BBC adaptations to a PlayStation game – that traps him ("It wasn't my fault that I had grown up") but strangles Rachel. Yet the cult, as cults do, slips free of its origins.

For the most part, Arthur remains as elusive as Mr Toppit. But, during his almost Victorian death scene, he is comforted by a tourist from Modesto, California, who witnesses his accident and feels that destiny has knocked for her. Through Laurie Clow, a large and lonely hospital DJ, the Hayseed books reach the wider world – at first via readings on her show, then as a cross-media sensation that bounces back to Britain.

Elton declines to dwell much on the appeal of Arthur's tales. If they have elements of Pooh, then Narnia and Watership Down perhaps figure in the mix. For all his gleeful parodies of critical tosh ("the tasks that Mr Toppit set Luke were variations on the myth of Sisyphus..."), they remain a blank space.

Instead, the comedy of misconstrual and embarrassment (a key word) dominates. Elton excels at slow-burning passages of hidden tension and comic cross-purposes: Laurie electing herself into the Hayman family; the funeral, with its set-piece calamity address by a movie-business lush; Laurie's excruciating visits with her – arguably – demented mother in a home.

In Dorset, in London and then in Los Angeles – where Laurie parlays her Hayseed discipleship into a networked TV chat show – familiar demons trudge out of the woods. Absent or delinquent fathers work their curse on both sides of the Atlantic; families are frozen by long-guarded secrets and lies; parents and children spar at smouldering loggerheads. Slightly predictably, adored children's tales compensate for domestic dysfunction; or, for the legatees, help to breed it. Lila, the German illustrator whose drawings first lumbered Luke with "ridiculous pantaloons", even lost her family in death camps.

However sound this insight, its execution as the novel unwinds feels like an anticlimax. Above all, the Los Angeles sections ramble on as the 18-year-old Luke summers with Laurie: too much routine drollery about showbiz flakiness. Elton thrives better amid the overcast miseries of Dorset than the sunlit hysteria of Tinseltown. At last, as Luke traces his sister's drug-addled path back to the woods of home, a sinister magic returns. Mr Toppit closes, as it opened, with a chillingly mingled hit of love, need and dread.