Scottish Mussel Talulah Riley Martin Compston

St Trinian’s actress Talulah Riley is clearly aiming for the whimsical Caledonian charm of Bill Forsyth’s Local Hero or Ken Loach’s The Angels’ Share as writer, director and star of Scottish Mussel, an eco-friendly comedy about pearl piracy in the Scottish Highlands.

Sadly, she falls some way short with her tale of a working-class Glaswegian chancer, Richie (Martin Compston, star of Loach’s Sweet Sixteen), who takes up pearl mussel poaching with a couple of eejit pals (Paul Brannigan and The Inbetweeners’ Joe Thomas).

The lads gamely set about their blundering pursuit of the freshwater mussels, any one of which could contain an elusive and valuable pearl. But Richie begins getting cold feet about the prospective moneymaking venture when he falls for Riley’s posh English conservationist Beth, who has dedicated herself to protecting the endangered molluscs.

It’s a slim enough story. Yet by throwing in drug-dealing gangsters, dodgy salmon farming and the romantic attentions of Beth’s Alpha-male American colleague Ethan (Morgan Watkins), Riley winds up with more sub-plots than she knows how to handle. The end result is an amiable enough romp, but the characters are thin and the slapstick action pretty feeble, while the dismal snot, spit and Viagra jokes should definitely have been thrown back.

Certificate 15. Runtime 94 mins. Director Talulah Riley

Scottish Mussel debuts on Sky Cinema Premiere on 7 December. Available on DVD & Digital from Spirit Entertainment.