The short way to describe The Seventh Day is ‘The Exorcist's Training Day’. Father Peter Costello (Guy Pearce) is a cynical, weathered veteran who has seen it all and plays by his own rules. Father Daniel García (Vadhir Derbez) is a wunderkind fresh out of the academy who will have to forget everything he has learned about the rite of exorcism. Both walk the city streets as some sort of 'undercover priests'. Like Father McGruder in Braindead, they kick arse for the Lord.

This material is rife with comedic potential (I’m reminded of Monty Python's Flying Circus’s Bishop sketch); it's a shame writer/director Justin P. Lange takes it so seriously. That there isn't a scene where Costello (a surname so closely associated with comedy that it took all of Jack Nicholson's gravitas to make it work in The Departed) and Garcia do a good priest/bad priest routine in the middle of an exorcism, or one in which the archbishop (Stephen Lang) asks for their bibles and holy water vials and takes them off the case, is simply unforgivable.

At the same time, Lange exhibits a fundamental ignorance of his movie’s subject matter. If the devil's greatest trick is convincing the world he doesn't exist, here he pulls something even trickier, hiding in the last place they would look for him: inside an exorcist. If Lange had bothered to do some research, he would know that “If Satan drives out Satan, he is divided against himself. How then shall his kingdom stand?” (Matthew 12:26). Now, the devil's plan is to put demons into bodies and not the other way around, but how could he keep up the charade of being an expert exorcist without casting out some of his brethren from time to time?