I’ve been a big fan of films that play hard and fast with psychosis over the years, and Filth is, I think, one of the best. It keeps you on your toes trying to figure put the difference between reality and the subject’s experiences, but it doesn’t do this at the expense of character and plot.

The protagonist here, Bruce (James McAvoy), is brilliantly portrayed with incredible pathos and drive. Apart from an unfortunate lull in the third quarter, which many films suffer from, he drives the plot forward brilliantly.

The super-plot is both straightforward and innovative. Frank is in line for promotion, but so are several other detectives in his Edinburgh unit. By setting them up, he manages to move himself up the ladder, building the likelihood of promotion by a steady process of elimination. His plan goes well until his own psychosis gets the better of him.

McAvoy is supported, though, by a cast of well-developed characters, all of whom are brilliantly relatable and portrayed by great actors.

The spectre of Trainspotting is heavy in the air with this film. There are familiar sequences and phrasing, but the whole is a unique and engaging story that warrants a second look.