Inside Prison: Britain Behind Bars

Thirty-year-old repeat offender Gemma, serving five years for burglary at HMP Downview in Surrey, talks about how her upbringing led her into a life of crime. She has a reputation for bad behaviour - which soon becomes apparent when she threatens a fellow prisoner. Meanwhile, new officer Jon Aldridge begins his first shift at HMP Bullingdon in Oxfordshire and seeks advice from one of the most respected men on the wing - top dog Anthony.

Friday means canteen day at HMP Bullingdon - where prisoners are delivered small treats like chocolate and shower gel which they buy with money earned from their jail jobs or sent in by friends and family outside. The only problem is, behind bars goods become much more valuable than they are on the outside, which can lead to debts - and payback.

In episode three, Search Team Officer Jamie is leading the hunt for contraband in HMP on the Isle of Wight. Five years ago, the prison became a specialist unit and is home to some of the most serious offenders in the UK, including more than 1,000 sex offenders.

In episode four, prisoners at Deerbolt young offender institution have started using a weekly religious ritual to distribute illicit items. The prison is home to 400 men aged between 18 and 24 and every Friday Muslim inmates from all wings congregate at the chapel for prayers. Violence Reduction Officer Nick has to review video footage in the wake of a number of fights breaking out in the chapel between inmates.