Christmas is a time for opening your hearts to others, and for Father David (Graham Skipper), priest at a failing provincial church, it also means opening his house. When locking up one night, he comes across Terry (Jeremy Gardner), who has been kicked out of his girlfriend’s house and is down on his luck. Putting him up for one night is the decent thing to do, except for Terry it’s an open invitation to make himself at home. Before long, he’s got his girlfriend (Taylor Zaudtke) there and David’s life is upended and his patience and faith strained.

Equally hilariously funny and grimly exasperating, The Leech is every good person’s nightmare. It’s handled beautifully by the lead trio. Skipper’s David is pious but doesn’t force a holier-than-thou attitude, but, frustratingly, does allow himself to be taken advantage of, as good people often do. Gardner epitomises our worst fears about the human race with Terry. His natural likeability means we can bear the character longer than we should, but we’ve all met a moocher like Terry at some point. We’re never sure if Terry is deliberately contriving situations or just ignorant of the results of his actions. As things get darker (how bad we won’t spoil here), we feel David losing control of his feelings as well as his home.

Writer/director Eric Pennycoff’s film is a spiralling nightmare of situations and tolerance. It also reminds us that sometimes being charitable isn’t always the best way to help people. You could almost treat The Leech as a home invasion in which the occupant is complicit. It might not be the warm and fuzzy film you’d want to settle down with every yule, but it’s a nightmarish ride that will leave you reeling.

The Leech is released on Blu-ray from December 5th.