Yuck! Is one of the first impressions that the viewer will get of Possum when Philip (Sean Harris) enters the decrepit and dirt caked house to meet his uncle Maurice (Alun Armstrong) who is in a similarly soiled state with a grating voice from the sewer. It sets the scene for a grim story that tries to dig into the desperation of the human psyche to punish and abuse, and escape.

The film is virtually a two hander, and Harris and Armstrong are sublime, as Maurice taunts Philip about his past, present and future. Entwined by secrets they may be but it’s a nothing relationship. It’s a performance that crawls over the screen, bordering on the repellent when Maurice leeringly offers Philip some disgusting looking sweets.

At its core it’s a dread story of abuse and mental illness. An almost unrelenting cruelty dished out with some relish too by Maurice. Philip (himself no angel) uses poetry and illustrations to escape the ordeals of the past. In the present his focus is on the destruction of the grotesque puppet Possum; a creation with long spidery legs and a human head. He’s tormented by visions and attempts to dispose of it are virtually futile as its presence is always there in some form. Philip’s trauma is palpable as his mind dredges the past to find a cause for him in the future.

Adding to all this is the disappearance of a boy whom Philip talked to on the train as he was travelling to the house, so marking him out as the prime suspect. The film thankfully doesn’t delve too far into this as it’s more a device to mess with Philip – as if he needs anymore - and sits clumsily in the film. Despite everything there is some sympathy for Philip as the film, slowly progresses the pieces fall into place and the full horror of his ordeal is revealed.

Composed with grubby hues it looks wretched and it genuinely has an atmosphere of decay which is superbly complemented by the Radiophonic Workshop soundtrack. Having said that for all the mould and muck and psychological aspirations writer/director Matthew Holness’s film doesn’t quite achieve the skin itching effect he may have been after. The visual disgust of Possum just overwhelms the psychological elements. Nevertheless, it’s a compelling film that straddles genres and its most certainly not for everyone.