If your sense of humour is sensitive, this may not be the show for you. Slick is an expert exercise in the grotesque: from concept to design to storyline it’s a grim comedy, made with little people and a big imagination.

Last year the Traverse was inhabited by Subway - a play by the company Vanishing Point. Vox Motus’ Slick occupies not just the same theatre space, but in many ways shares the same vision – a dystopian urban Scotland, real yet unreal, like a place remembered in a dream. But while Subway laid out a whole city and culture for us, Slick takes just one tenement block and two broken families.

Wee Malcolm Biggar is 9 ¾ and approaching a turning point in his life. His parents are an unpleasant pair; fixated by money, they have no regard for their cheery, skateboard-loving son. We meet the family on the verge of eviction at the hands of their perverted landlord, Jerko Dreich. Jerko lives in the apartment above the Biggar family and above him, in an ascendancy of the grotesque, lives his mother, Mrs Dreich. Abuse, violence and vanity cloak their dirty tenement block in a modern-gothic Glasgow. As the story unfolds (literally, from two set boxes on stage), we discover a web of rapacity. This would be a tale of unremitting bleakness (and nearly turns out so), but for the chink of hope that is wee Malcolm.

The storyline is crazy: a live action cartoon which runs the gamut from There Will Be Blood to Reservoir Dogs, in its theme of oil and its gun-packing denouement. But amidst its lunacy there are strong fairytale themes. Early on the family strike it lucky in the most unlikely of places, finding their lavatory is actually a well of black gold. The association of loos and filthy lucre contrasts starkly with the play’s ultimate emblems of happiness – the simple freedom and security of a skateboard and a safety helmet. At heart (and Slick does have a lot of heart, jammed in with the rectal jokes and the penis pumps) – at heart it’s an old-fashioned, socialist-tinged morality tale that gives us bad things happening to bad people. And then there are the brilliant, funny throwaway lines referencing the energy crisis and child soldiers.

But the genius of Slick is less in the tale than in the remarkable manner of its telling. The Biggars and the Dreichs are living puppets - strange dwarfish caricatures of people – like figures seen in a circus mirror. The actors’ heads perch above truncated fabric bodies, hung like bibs around their necks. Each character is composed more often than not of two human performers – one providing the face and the other the hands (or, in one inspired moment, the feet). Alongside the five character roles, the five performers (Jordan Young, Angela Darcy, Robert Jack, Mark Prendergast, Cora Bissett) are also the narrative voices and the adroit stagehands. Clad in black, they manoeuvre the set and whisk out costumes like so many existentialist Debbie McGees.

Hand in hand with the absurd funnies and scatology of the script, there are some lovely flourishes of visual wit – when attention is drawn to a plastic puppet hand, puncturing the make-believe, when a burst of aerosol serves for a spurt of snow in a James Bond homage, and when beams of light shine through bullet holes in a roof. There’s also the star of the design: a transformative, pop-up set, which for most of the show appears as a deceptively simple backdrop. But to catch the show at its full frontal best, you do need to sit facing the stage, as it’s performed in thrust, and the sides miss out on some of the impact. Slick is inventive and bizarre, stomach churning and charming. And it’s one of the best things on the Fringe this year - so get there early and get a front row seat.