T his has nothing to do with Ian Dury; rather, it is a brisk, effective British indie thriller informed by the legend of Robert Louis Stevenson wrestling his shadow self while writing Dr Jekyll and Mr Hyde. The present-day equivalent proposed by writer and director Matt Harlock is BritLit posterboy Will Mercer (Danny Horn), much admired for his debut novel A Random Act yet presently mired in indecision over a follow-up that seems likely to cost him relationships, representation and reputation alike. Retreating to a friend’s garret, he is woken by a builder: bullet-headed, charismatic hulk Mikey (Joe Sims), who merits and invites closer literary study. Mikey is unarguably an arresting character – a very handy golem in overalls – even if we worry about the path he’s leading our man down.

No prizes, then, for guessing which David Fincher film provides the template here.…