WHAT does going to prison really entail? Charlie Ryder knows first hand because he has been there. In this one-man show, he gives a rare and honest insight into the prison system, putting a face to what is often the faceless idea of "the prisoner". He's not a professional actor, but he is a wonderfully open and impassioned performer - a genuine person who you would not want to see behind bars.

As he relays his story of being inside for 16 months, after getting involved in violence while protesting against racism, he portrays what has obviously been a deeply traumatic time for him. In particular, the dehumanising effects of well-known procedures, such as being strip-searched, are clearly examined in his spotlight.

Using clothes pegs as people, household objects as props and a series of hand-drawn pictures, Charlie has a child-like vision of the world that works especially well when paired with the very adult realities of the British justice system.

It is difficult to come away from this piece thinking that prison in its current manifestation is a good idea - and that is Charlie's aim, to make you question the system, and it is something he definitely achieves.

However, this is a very rough and ready play that suffers from its eclectic narrative. Charlie really needs to speak up when he's playing himself (ironically, he's great when being other characters) and could do with a good director or producer to mould things into shape. This is an effective and important play that, with professional development, could be truly powerful.

• Until 27 August. Today 8.30pm