Haunted by visions of ice-and-bubbles reminiscent of a 7-Up ad, Shirley Henderson is Kath - a mixed-up Lancashire gal determined to uncover why her sister went missing. With a spooky wasteland of sands jutting out from Kath's desolate fishing town, Frozen could so easily have entered "There's something strange out there..." chiller territory. Instead, though, it prefers to champion its low budget with floods of stark dialogue as a doleful cello warbles away as the only backing.
The outcome is a first hour that feels like a midweek TV drama. It's unfortunate, then, that this slow-burning baptism of boredom comes with a surprisingly effective sting in the tail. Alas, although Henderson's performance is almost enough to bring us in from the cold, the ambitious psychological concept is sold short long before its unveiling.