Wonky light bulbs, religious iconography, empty rooms, old photos, fitful sleeps, strange humming, ominous-looking Christmas Trees, cleavage - Nicholas McCarthy doesn't leave too many boxes un-ticked on the horror movie checklist for the feature-length version of his acclaimed short film. But to this tried-and-trusted mix he's also added newcomer (and former Lady Gaga dancer, but grumps, don't hold that against her) Caity Lotz, and it's her a-ha performance that compensates for The Pact's ho-hum.

Lotz plays Annie, a troubled soul who arrives at her just-deceased mother's home following the disappearance of her sister Nicole (Bruckner). A recovering drug addict, Nicole was clearing out the bungalow and making funeral arrangements when she vanished into thin air, and while Annie thinks she's relapsed and will eventually show up, it's not long before she starts experiencing strange things. 550 Claremont Avenue has many dark secrets - some of which Annie may have chosen to forget.

With an opening that recalls both Halloween and When a Stranger Calls, first-time director McCarthy announces himself as a man who knows his horror history and, just like John Carpenter and Fred Walton before him, shows that he can make the most of a small space and budget. Unlike those two directors, however, his hero isn't the most sympathetic of characters - something that gives a little more edge to the familiar plot and Lotz's performance. After this, we should be seeing more of the Californian: the camera likes her; she has real screen presence and her experience in both dance and martial arts and stint on Mad Men (she was Stephanie in season four) says she could have a very interesting career. As a calling card, The Pact is very effective.

Where the film falls down is in the final stages. After doing good work with things that go bump during the day and the ever-building menace, McCarthy introduces a cheese and chutzpah twist that may result in bad-curry groans from those sitting nearby, or indeed yourself. When a fan of the far-fetched deems a movie too far-fetched a director is in trouble; and McCarthy's explanation is so ludicrous that suddenly the lad in the body stocking at the end of Signs doesn't seem quite so bad. Special mention must also go to the fact that although Lotz's character is meant to be hiding for her life, she manages to make only slight less noise than Napalm Death playing in Ron Black's Dawson Lounge.

Far worse films have been granted sequels – but that doesn't mean one is needed.

Harry Guerin