The Soska Sisters’ long-awaited new film is a visually mesmerising and disturbing attack on the morals of those who preach purity and the power of sexual therapy, no matter how far that goes.

Peter (Aramis Sartorio) has a loving wife (Sylvia Soska, sporting a blonde wig) and twin daughters (Alanna and Brianne Finn-Morris), and is due to be away for a few days ‘on business’. Checking into the penthouse suite of a luxurious hotel, Peter is faced with Mistress Satana (Jen Soska). As she submits him to a most degrading and painful form of punishment, he’s forced to confront himself and his past.

If American Mary pushed the boundaries of body modification, On the Edge does the same when it comes to BDSM. Sartorio is a famed adult film star so is used to the type of content that makes up most of the Soska’s movie but it’s still enough to have most males in the viewing audience wince more than a few times. As the dominatrix, Jen puts in a remarkable performance, she melds scary (and there are moments when she’s downright terrifying!) into sexy perfectly. Even though things get extreme – and the lines between reality and the psychotropic blur – the adult nature of the performance doesn’t lean toward exploitation or titillation. It’s a matter-of-fact depiction of a sex worker who holds all the power and agency, which is refreshing.

While we’re not sure whether Peter knew what he was letting himself in for by booking his room at first, as the film progresses, things become even more fucked-up, and as such, it becomes clearer. Peter has clearly got issues to work through and his 36 hours in the nightmare of the penthouse might be just what he needs.

Despite not boasting the gore that has filled the Twisted Twins’ earlier films, On the Edge is their most challenging watch yet. It’s also the one that will linger long in the mind as we ruminate on the themes and execution. Religious hypocrisy is low-hanging fruit (well, apple at least), and the sisters fill the dialogue with references to Lilith and the like that will make your local priest explode.

It certainly won’t be for everyone and isn’t their most commercial film, but it’s not one that can be dismissed too easily.