AN impressive, bizarrely star-studded cast can’t save this limp British horror-comedy that barely has two decent gags to rub together while forgetting to be scary.

Layabout Northern teenager Don (Peaky Blinders’ Finn Cole) is sent by his widowed and fed-up mum (Jo Hartley) to an illustrious boarding school. Despite struggling to see the point much less able to easily fit in, he strikes up a friendship with snarky roommate Willoughby (Asa Butterfield), lands on the wrong side of the power-abusing “upper six” student Clegg (Tom Rhys Harries) and immediately falls for beautiful schoolmate Clemsie (Hermione Corfield).

Whether by design or happy accident, the film is lent some surprising news-leaning topicality: The nearby fracking operation which funds the school has disturbed a sinister, seemingly blood-thirsty species of subterranean creatures now with easy access to the surface thanks to a giant sinkhole the drilling company has opened up.

Any promise fades as film gives way to a horror-comedy that simply isn’t scary or funny. Any zippy energy brought to the set-pieces by director Crispian Mills (A Fantastic Fear of Everything) sinks into the mire of a stodgy script which has a stream of set-ups but no real punchlines, while social commentary on educational elitism is simplistic at best.

It feels like several films bolted together into a Frankenstein’s monster, groaning and moaning as it wanders through an increasingly tiresome and predictable plot.

An eye-catching cast are more of a “what the hell are they doing in this?” curiosity than any sort of great value. Simon Pegg feels at sea in an unnecessary subplot as a lovesick housemaster desperately wanting his aid worker girlfriend (Margot Robbie) to come home. As if they come two for the price of one, Nick Frost pops up but can’t do much to elevate the material as the leader of a group of anti-fracking forrest-dwellers. And despite the already outlandish world in which it exists, Michael Sheen feels conspicuously out of place as an OTT headteacher referred to as “The Bat”.

The younger cast give it their all but they’re hampered with characters that all feel like a series of half-cooked quirks rather rounded people. As much as they’re doing battle with monsters, they also have to contend with too many underdeveloped subplots.

Plenty of films have played around in the bloody sandpit of horror pastiche, but the script simply isn’t sharp enough here to sell as proper reverence, instead coming off as a cheap wannabe with a dislodged funny bone and very little bite.