Shirley Henderson is one of those "oh, that's whatsername" actresses who, since stepping up from TV’s Hamish Macbeth, has been popping up on the big screen as everything from Bridget Jones's best mate to Hogwarts' deceased toilet attendant Moaning Myrtle.

Looking half her age (she's 40) and with the voice of someone half that again, she finally gets a well-earned leading role as Kath, a quiet northern lass obsessed with her sister Annie who vanished two years previously.

Despair leads to a suicide attempt which in turn leads to counselling from the local vicar (Roshan Seth). As he tries to help her move on, Kath steals a CCTV recording from the police and takes it to a friend at the dockyard from whence it came.

Through her obsessive investigation, she learns a lot about Annie and the men in her life. Kath is also convinced that Annie is trying to reach her through visions which can't be explained away rationally.

Shooting on digital video on Lancashire’s northern riviera creates a suitably bleak environment for writer/director Juliet McKoen's deliberately rough-edged first feature.

Seen from Kath's reality-skewed viewpoint, it is never clear where the film is going which works for a time but the ice of the story begins to looks thin from the halfway mark.

Instead of having Kath staring off into the middle distance with such monotonous regularity, McKoen could have explored more interesting ideas, like having an Asian clergyman in northern England.

She also gives no explanation as to why Kath would be so unaware of her sister's behaviour, given the smallness of the community and how close they were supposed to have been.

It was never going to be a satisfying fish-and-chip supper of a movie, but Frozen never offers more than cinematic crabsticks.

Elliott Noble