This year marks the centenary of J.M. Barrie’s Peter Pan. None of the planned commemorations of this event is likely to be as interesting as An English Gentleman, Sky Gilbert’s fourth novel and easily his most accomplished fiction to date.

At the centre of this literary mystery is the 1921 drowning of Michael Llewelyn Davies, one of five brothers adopted by Barrie after the death of their father. Michael was Barrie’s favourite and the main inspiration for Peter Pan. Two thousand letters are said to have passed between them, letters assumed lost until – in Gilbert’s imagining – a small clutch of them turn up in the gay community of New York City. The fictional letters are willed to Manny Masters by his friend Leslie Sexton, a Barrie scholar. Sexton believed that Captain Hook was a gay figure based on Oscar Wilde, and that the creator of Never-Neverland was a pederast. The letters, he claimed, proved it. Manny sets out to disprove that claim using the very same letters.

Nothing in Gilbert’s previous fiction prepares us for the deft touch with which he handles these epistles between the famous playwright and his charge. Especially adroit is the way the letters are filtered though the unreliable Manny, whose own obsessions with the nature of Victorian innocence and sexual repression colour everything he relates.

The novel is a bit lopsided: as the action moves away from the relationship between Barrie and Michael, and into Manny’s relationship with Alan Peche, his own “lost boy,” the tone becomes ponderous.

Those familiar with Gilbert’s work as both a novelist and a playwright will find here a lot less bile, blood, and other bodily fluids than they might expect. The anti-gay diatribes Manny descends into are matched well against theories involving Knights Templar and Freemasons. In Gilbert’s previous novel, I am Kasper Klotz, similar diatribes were done solely for belletristic effect; here they reveal a depth of character that is sadly moving. Is it possible that Sky Gilbert has finally grown up?