Six celebrities are participating in a four-part constructed documentary series where they will be locked up as prisoners for eight days, in decommissioned HMP Shrewsbury, to investigate what life is really like behind bars.The six well-known inmates will be incarcerated with a variety of real ex-criminals, including those who have served long sentences for serious crimes - although all are now reformed and have agreed to re-enter prison for this series. The well-known inmates will have the opportunity to interrogate their cellmates on their prison experiences and former crimes - as well as examine the impact of the system on them for better or worse.Run by a former prison governor, with 20 years' experience in some of the UK's toughest prisons, and former prison officers, the inmates will live by current UK prison rules.