Season three ended on an upbeat note with the Litchfield inmates swimming in a lake, having escaped through a hole in a fence.
But as season four begins these quasi-idyllic scenes quickly came crashing down, as Mei Chang tells Piper: “I think Ms Rosa got cancer from that lake.”
The women’s temporary escape sets in motion one of the overarching themes of the season, the ever-growing tension between the inmates and the new militarised prison guards.
Season four introduces a new batch of private-sector COs, whose totalitarian and often-violent attitudes push the prison to the brink of riot.
The 13 episodes are among the show’s darkest to date, tackling issues such as police brutality, racism, mental illness and rape.
Here is a recap of where we left the major players ahead of this week’s season five release.
Alex and Lolly
Alex was dubbed paranoid throughout season three after she became convinced that her former drug boss had planted a hitman in Litchfield.
But as her fellow inmates swim in the lake, Alex comes face to face with an assassin who had gone undercover as a prison guard.
Lolly comes to Alex’s rescue and fights off the attacker, stamping him in the throat until he stops breathing.
When Alex later returns to the scene of the crime, she discovers that the guard is still alive and is forced to suffocate him with a wad of tissue.
Orange is the New Black: Alex and Lolly killed an undercover hitman
Frieda later helps her to dispose of the body, cutting it into six pieces and burying it bit-by-bit – good “murder math”, according to Frieda.
Alex spends the rest of the season wracked with guilt and terrified that the increasingly unstable Lolly will reveal her secret.
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Lolly begins suffering from delusions and at one point attempts to dig up the body.
She confesses the murder to Healy, who puts it down to her imagination.
When the body is eventually found, Healy realises that Lolly isn’t lying and sends to the psych ward.
Orange is the New Black: Piper declares that she is 'gangster with an A'
Middle-class felon Piper took a back seat throughout season four as the show developed into a true ensemble piece.
After framing Stella and sending her to maximum security, Piper declares that she is “gangsta, like with an A at the end”.
She finds herself in a bitter feud with Maria Ruiz and the Dominican inmates, who open a rival panty business.
Piper attempts to start a neighbourhood watch-style group to police her rivals, which backfires when it inadvertently creates a white supremacist group who later find out about Maria’s activities.
Terrified that her own activities will be exposed, Piper plants panties in Maria’s bunk, landing her another three to five years in prison.
In retaliation the Dominicans rush Piper and drag her to the kitchen, where they brand her with a swastika.
The incident breaks Piper and crushes her new-found bravado. Towards the end of the season she focuses on helping others and reconciles with Alex.
Orange is the New Black: Sophia spent much of season four in the SHU
Litchfield’s sole trans inmate spends the majority of season four in the SHU, where she becomes increasingly depressed and tries to take her own life.
In the penultimate episode, Sophia is allowed back into the main prison where she discovers that Maria’s gang has taken over her salon.
Gloria, who was partly responsible for sending Sophia to the SHU, orders the Dominicans out of the salon, and helps Sophia with her wig as a kindness.
Orange is the New Black: Pennsatucky was raped throughout season three
Pennsatucky was systematically raped by CO Charlie Coates in season three, and spends season four struggling to come to terms with what has happened to her.
Initially she is determined to protect her fellow inmates from her attacker, and confronts Coates about whether he is forcing himself on another woman.
Coates is shocked when Pennsatucky says: “I just want to make sure you’re not raping her, is all."
He tries to excuse his crimes, replying: “But I love you. I told you that. And I said it when … When I said it. So that makes it different."
Later in the season Pennsatucky decides to forgive his “mistake”, driving a wedge between her and Boo.
In the finale, she tells Coates: “Toast can’t ever be bread again, but I like talking to you,” before kissing him.
Orange is the New Black: Poussey was accidentally crushed to death
The second half of season four sees Poussey and girlfriend Soso grow closer as their sentences draw to a close.
Incarcerated TV chef Judy King promises Poussey a job once she is released, and the loved-up couple begin planning a life together on the outside.
In the penultimate episode Poussey gets tackled during a stand-off between the inmates and guards, and suffocates to death.
Her gruesome end mirrored the death of Eric Garner, who was killed when a police officer put him into a chokehold.
Soso is devastated, as is Poussey’s best friend Taystee.
When the inmates discover that the guards will not be brought to justice, they launch a full-scale prison riot which leads into the season’s big cliff-hanger.
Orange is the New Black: Daya pointed a gun at CO Humphrey in the season four finale
Daya begins the season devastated after her baby is taken into foster care as a result of her mother Aleida’s interference.
When Aleida is released early for good behaviour, she vows to get custody of the child but leaves Daya without a guiding force.
Alone, Daya falls in with Maria and her violent gang and gets caught up in the riot sparked by Poussey’s death.
In the final scenes CO Humphrey pulls a gun on the inmates but fumbles and drops it to the ground.
Daya picks up the weapon and points it at the white supremacists, before turning it on Humphrey to the delight of the inmates.
Season five will pick up where season four left off, with Daya’s finger on the trigger.
Dascha Polanco, who plays Daya, has teased: “I could see her pulling the trigger. Daya's definitely experiencing some postpartum depression.
“She might pull back and think about being a mother and not wanting to miss the opportunity of being with her child.”
Orange is the New Black season five is released on Netflix on Friday June 9.