A deliciously dark festive horror comedy in which 17-year-old babysitter Olivia DeJonge’s job takes a very creepy turn.

First, she is taken aback when her long-time charge, a precocious 12-year-old (Levi Miller), cracks open a bottle of champagne and starts making romantic moves on her after his bickering parents (Virginia Madsen and Patrick Warburton) leave for a Christmas party.

However, the evening soon becomes even more disconcerting. Then a mushroom pizza arrives that hasn’t been ordered,  a brick is thrown through an upstairs window – and a shadowy, hooded figure is lurking outside…

Films in which teenage babysitters are terrorised by a deranged psychopath are nothing new, but director and co-writer Chris Peckover has a few nasty new tricks up his sleeve here.

It’s best not to know too much about the plot going in, save that the film, which is rather like a grisly twist on Home Alone, has an unexpectedly sadistic streak – and that both DeJonge and Miller turn out to be far more resolute and resourceful than you might at first imagine.