A gender-switched riff on Stand By Me sounds like an intriguing idea – a dead body is discovered by four pre-teen girls – and interesting things do happen in this film at first, in that it declines to conform tonally to what you expect; and yet the quirky-dreamy YA style persists. However, there is something uncertain and soft-centre about what follows, and the plot unrealities make it very silly.

Lola (Sanai Victoria), Mari (Eden Grace Redfield), Daisy (Madalen Mills) and Daisy (Lia Barnett) are four best friends in an American suburb, whiling away the long hot summer before they start middle school. Rambling aimlessly through some woodland outside town, they are stunned to discover the corpse of a man, and find themselves mostly reluctant to tell the police or their parents: they want to savour this bizarre, rare secret and also realise that once the alarm is raised, they will be fiercely questioned and feel like they are in trouble even though they aren’t.

This paralysis brings its own complication: the longer they leave it after the discovery, the more trouble they will indeed be in. It’s a sound, shrewd psychological insight. But then they move the body and discover a receipt from a bar (that time-honoured pulp-thriller plot move) and go there on a cute detective-jaunt to find out who the corpse was. Daisy even borrows her mum’s gun and gets to fire it at a padlocked door – all without consequences. Did she ever return the gun to her mum? Who knows?

The dead man may symbolise the looming concept of maleness in their lives, the absent or emotionally unavailable father (only their mums are shown on screen). Or maybe he symbolises the looming relevance – or irrelevance – of boys. Either way, the ending is a tiresome new-agey cop-out and a lot of viable ideas have gone to waste. A disappointment.

• Summering is released on 2 December in cinemas.