As Series 4 opens, the story from Series 3 continues. Larkhall welcomes a new Governing Governor to replace the dismissed Stubberfield and then the blackmailed Stewart. Neil Grayling takes over as Number 1 and intends to revolutionise the prison, not foresaking G Wing. Grayling wants to reform and privatise things, especially the canteen, much to the annoyance of the inmates. G Wing Governor Karen Betts cannot cope with the backlash from the changes, giving Grayling the perfect opportunity to demote her and give Fenner the post as Wing Governor. Betts is now realising the truth about Fenner, which Stewart and Dockley tried desperately to warn her of. Fenner enforces his authority but does not last long. Although Hollamby gets a chance at the job, Betts is eventually returned to her post, determined to make life hell for Fenner! However as the murder of Virginia O'Kane is investigated, Fenner learns that Atkins could be innocent and Pervis is the culprit, trying to do the dirty on Fenner. Atkins and Fenner join into an uneasy alliance to destroy the Peckham Boot Gang once and for all. The series meets an explosive end with glamorous inmate, Snowball Merriman blowing up most of G Wing to make her escape with Yvonne's son. Betts, Fenner and Atkins are determined to see that Snowball does not get away with her murders. This series will keep you on the very edge of your seat, with the usual death, drugs and mayhem!