Season 4 Part 1
Diane took vacation with her daughter to England and while there, she met a police officer and fell in love. They got married and she's now living there. Diane contacted Tim McManus through a letter describing how she's now married and very happy.
The arrival of Officer Howell spells trouble, something Diane finds out when she attempts to be friendly with this new female hack. Diane's mother finally succumbs to cancer. Later on, Clayton Hughes accidentally hits Diane in the head with his nightstick. The tension between Howell (who sleeps with McManus) and Diane (who also did in the past) leads to a brawl in the break room. On New Year's Eve, when all hacks and staff are placed on alert for a possible riot, Diane tells McManus that she's taking an immediate leave and if he protests, she'll quit.
After helping McManus recover from being shot, she returns to Em City. She, like everyone else, gives her account of the riot and its cause. She also participates in setting up Schillinger on a conspiracy to kill Beecher. However, the Scott Ross murder refuses to go away, and Diane pleads with McManus for him to lie for her and keep their stories straight.
Oz's first female guard is a single mom with a sickly mother. She begins a brief affair with McManus but breaks it off. New inmate Scott Ross arrives and immediately tries to re-bond with Wittlesey. Her ex-husband and Ross were biker partners in the past and she can't stand Ross. When budget cuts eliminate her overtime pay, Ross proposes she smuggle cigarettes in, he'll sell them to the inmates and give her a cut. McManus finds out about this arrangement and orders Diane to stop. She does and tells Ross only Ross has no plans to stop and threatens to expose her. As she searches for solution, a riot breaks out in Oz and she's taken hostage with other officers.