After a personal struggle with her sexuality, the battle to stand as an authority figure in Larkhall, and the breakup from her fiancé Sean, she goes on holiday to clear her head.
When Simon is demoted after Shell Dockley, Denny Blood, and Shaz Wylie escape, Helen becomes the new acting governor of Larkhall.
An out and proud lesbian, Nikki is an outspoken strong-minded inmate who clashes with Helen at the start of the series.
Nikki organises a peaceful protest when some of the officers brutally restrain Femi Bada, a non-English speaking inmate who is separated from her kids, which escalates into a riot and Helen ends their relationship again, though she continues to help her with her appeal.
Michelle "Shell" Dockley is serving life for the kidnap, torture, and murder of the woman who stole her boyfriend.
Shell returns in series 5 when she is found by Jim, Collin Hedges, and Ken Pearce at an erotic dance club where she is performing before being arrested and sent back to Larkhall.
She is pregnant and re-enters into a relationship with Jim, which ends when Shell is transferred to a psychiatric hospital shortly after giving birth.
He told Yvonne Swann of the Daily Mirror that he had been in debt, welcomed the role, and that "it certainly put [his] name on the map" as an actor.
Lorna Rose is a young prison officer who is blackmailed by Zandra Plackett and Shell to smuggle in drugs for them, which she is sacked for.
Sylvia "Body Bag" Hollamby is the longest serving prison officer on the show with Johnston and Saunders, being the only other characters to last all eight series.
Zandra Plackett is a drug addict serving ten months in prison for credit card fraud.
She tries to seduce various male officers without much success: Dominic, Josh Mitchell, Neil Grayling, Mark Waddle, Barry Pearce, and Jim.
Malcolm Nicholson is Larkhall's senior medical officer in series two and three before being fired by Helen's serious concerns about his inability to diagnose the mental illness of "Podger" Pam Jolly.
Just before Malcolm puts the needle in, Phyl Oswyn and Bev Tull appear on the balcony having discovered diamonds and a gun in their hotel suite and now escaping from their owner.
Barbara "Babs" Hunt is a middle-aged, middle-class woman, who is sent to prison for three years on a manslaughter charge for mercy-killing her terminally ill second husband.
Babs is put into segregation while Tessa is inducted into the wing – she manages to then threaten Karen Betts with a syringe of HIV-positive blood.
Hunt is devoutly religious, attends chapel frequently, and the prison officers give her significant responsibilities, which she sometimes abuses.
They both escape with Shell in series 3, but Shaz has an accident and is brought back to prison, where she is bullied by Al McKenzie and Maxi Purvis.
Maxine "Maxi" Purvis is the head of the Peckham Boot Gang and tries to become Top Dog of G-Wing but fails miserably when she gets beaten up by Shaz.
She initially bullies Shaz, gets beaten up by Yvonne, kills Virginia, and helps her sister Maxi commit suicide.
Virginia O'Kane is an elderly brothel owner who is murdered by Al. Neil Grayling is the governor of Larkhall prison.
As a result of the bomb, Snowball becomes the most hated prisoner ever, with Saunders, Johnston, and Tina giving her a raw chicken for dinner.
Phyl becomes my favourite top dog after Yvonne's escape, but loses the position in a power struggle with Frances.
Natalie Buxton was sent to Larkhall for income tax fraud in the first episode of series six but was transferred when her real crime was exposed by Frances Myers (Eva Pope).
She returned four episodes later and she mainly featured in an antagonistic role while in a power struggle with Wing Governor Frances and manipulating and being violent towards inmates.
Janine and Darlene become Natalie's cronies, and after they discover Arun is a trans woman, they begin bullying her worse and demand that she be sent to a men's prison.
Stella attacks Joy with a smashed glasses lens attached to a toothbrush, and new prison officer Mandy Goodhue saves her.
When Darlene sets fire to herself on the landing of G-Wing, Donny saves her and Joy commends him for his quick thinking, saying that he is allowed to keep his job.
When Lou discovers that a young girl, Vanessa Andrews, is being used to smuggle drugs into prisons using her vagina, she confronts Natalie after Pat snitches on her.
When Mandy searches young girl Vanessa Andrews, she cannot find anything abnormal on her, but it is later revealed that she was hiding drugs in her vagina to give to Natalie.