The Canadian actor Jay Baruchel – a Judd Apatow regular and the voice of Hiccup in the family animation How to Train Your Dragon – has directed an exasperating serial killer-slasher. He brings to the genre a script with brain cells spilling out of its victims’ smashed skulls and the acting is a cut above – performed in an easy improvy naturalistic style that feels very Apatow. But inexplicably Baruchel and his co-writer Jesse Chabot staple on a finger-waggingly pious and pointless message about violence in entertainment.

Jesse Williams stars as Toronto comic book artist Todd, who’s struggling with the final issue of his mega successful R-rated franchise Slasherman. The series is based on actual events, half a dozen grisly unsolved murders that took place along a stretch of Interstate 90 in the late 80s. To get his creative juices flowing, Todd takes a road trip along the highway, slumming it in scummy motels with his girlfriend, personal assistant and goofy business partner (nicely played by Baruchel). Todd, a left-leaning liberal who would no doubt describe himself as a feminist, is unnerved by fanboys at a comic bookstore signing. While he has intellectualised the gut-wrenchingly horrible images of tortured and disembowelled women in his comics, to the creepy guys dressed up like his protagonist in welders masks, Slasherman is a hero.

Worse, the real-life serial killer (Simon Northwood) is at it again, and clearly he’s been reading Todd’s comic books – giving the film a couple of genuinely scary early kills. The local cops think Todd is to blame for the new spate of murders: “Even if you didn’t kill this girl you may as well have. Your mind is all over this mess.” And with this, the movie falls apart with some moral handwringing that will likely infuriate genre fans, and for everyone else, feel like a tired airing of the debate around violence in movies – all the more objectionable in a film with its fair share of mutilated female victims.