The officers at Long Marsh men's prison each have their own take on the job. Their stories reveal that there's more to life in prison than people know. Officer Leigh lives for her job, but when new recruit Rose arrives, C Wing will never be the same.

Officer Leigh Henry is coming under increased pressure to produce her birth certificate, to secure the promotion she so desperately wants; with the help of her colleagues, Rose starts to find her feet in this terrifying new world.

Leigh considers crossing the line between officer and criminal, some of the wing's residents are trying dangerous new ways to get high; Rose carries out a dangerous mission, and finds herself trapped in a potentially deadly double bind.

Leigh becomes increasingly isolated from her sceptical colleagues; a guilt-ridden Rose takes a chance to make amends; Toby's suspicions of Leigh lead him to his own investigations.

With C Wing on lockdown, the prisoners' mental health reaches crisis point in an under-resourced and chaotic system; Rose sees an opportunity, and Toby threatens to escalate his suspicions.

As Long Marsh comes under the spotlight, life on the tense and paranoid C Wing is altered forever, and everyone is a suspect; Leigh reaches breaking point when she learns that she may have played a more direct role in the murder than even she knew.