The archaeologists uncover a 19th-century prison with a difference in Wiltshire. Devizes House of Corrections was one of the first panopticon style prisons built in the UK, with its all-seeing central guards' tower which allowed just a handful of guards to monitor and control the lives of hundreds of prisoners. The team want to uncover the prison's lost structures, reveal the secrets of what went on behind its walls and discover just how secure and inescapable it really was.