'Category B' is a sharp and hard-hitting play about the brutal power structures of prison life. It is set in a Category B prison, where all offenders are placed after they are first convicted: it is tough, and dangerous, and compelling. Inside C Wing, Thames Gate Prison, it's the screws that have the keys, but all too often it's the prisoners that have the power. Williams's play was first performed as part of the 'Not Black and White' season at the Tricycle Theatre, London, in 2009.