Taking its title from a term used by gang members for people not involved in a crime, Straightheads is a brutal and unsettling revenge thriller that sinks to the same unnecessarily violent depths as its characters.

Documentary filmmaker Dan Reed, making his dramatic feature debut, shows restraint in his depiction of a sickening assault and rape at the beginning of the film, which devastates a businesswoman and her younger lover.

The narrative cuts to the aftermath; the gruesome details thankfully unseen.

However, as the plot careers towards its horribly inevitable conclusion, Reed returns (via flashback) to the events of the fateful night before his much-abused protagonists allow their hunger for vengeance to consume them.

"Do you know what they did after they finished with me?" screeches the brutalised heroine. "They laughed. I wish I could just walk away, but I can't."

Those with a weak stomach should look away as she takes matters into her own hands.

The dark desires, which propel the characters on their journey of self-destruction, might be more compelling if Reed's screenplay were stronger.