Ryan Reynolds manages to be both scary and sweet in this darkly funny, disarmingly weird horror comedy.

He plays a charmingly chipper paranoid schizophrenic factory worker who embarks upon an accidental killing spree, egged on by his talking cat.

This is bad news for his co-workers Gemma Arterton and Anna Kendrick and long-suffering therapist Jacki Weaver.

The sight of severed heads in a fridge is deliciously sick, though it won’t, needless to say, be to all tastes.

That Reynolds retains our sympathy amid the gore is largely down to his goofy charm, abetted by the film’s colourfully cartoony look, an in-your-face mix of surrealism and kitsch from Iranian-born director Marjane Satrapi (best known for the Oscar-nominated animated feature Persepolis).