There could surely be no better setting for an adaptation of William Golding’s Lord of the Flies than Regent's Park's Open Air Theatre. The atmosphere of the novel is richly evoked by Nick Powell’s score, Mike Walker’s sound design and Jon Bausor’s set, a wrecked aeroplane with its cargo strewn generously around the place. So beautifully integrated is all this into the theatre’s verdant surroundings that we feel as if we have come across the site of an actual plane crash.

The story of the group of school boys stranded on an desert island after a plane crash will be familiar to most audience members, so well known is Golding’s 1954 novel. What begins promisingly, with the boys electing a leader and deciding on a scheme that will increase their chances of being rescued, ends with chaos, cruelty and murder.

Nigel Williams’s adaptation successfully updates the language and tone of the original, bringing the story to the present day without losing the tensions and tendernesses that exist between the characters, but it was a mistake to try to turn this slim story into a two-hour show. The genius of Golding’s novel is not in its plotting, but in its exploration of human nature and its shocking conclusions about mankind’s capacity for empathy and violence. Timothy Sheader’s staging offers some very fine moments of storytelling, and his young cast give mostly excellent performances – including an unusually assured turn by nine-year-old Harrison Sanostri as 'littlun' Percival – but too much of the show’s dialogue feels like it’s there to pad out what should have been a one-act play.

The second half is stronger than the first – it is a spine-tingling moment when night finally falls over the auditorium, echoing the arrival of metaphorical darkness in the boys’ island society – but too much time is spent on circular discussion and overly repeated choreographic motifs for this show to properly convey the horror of Golding’s novel.