Eighteen-year-old Ritchie Tozer (Olly Alexander) is leaving the Isle of Wight to go to university. In London, Roscoe Babatunde (Omari Douglas) walks out of home after his parents make a shocking discovery. And Colin Morris-Jones (Callum Scott Howells) arrives from Wales, to start a new career on Savile Row. The three boys meet, and life will never be the same again.
As the year unfolds, the boys – along with fellow student Ash (Nathaniel Curtis) and their best friend Jill (Lydia West) – form a gang and move into a flat, christened the Pink Palace. And there, they start to become who they truly are. But a distant threat on the horizon means that life in the 80s might be all too precious.
While Ritchie (Olly Alexander) and Jill (Lydia West) embark on a scheme to become professional actors, Colin (Callum Scott Howells) is excited to be offered a trip to New York. And Roscoe (Omari Douglas) hides his fury when he finds himself excluded from his sister’s wedding. Meanwhile, when an old friend, Gloria, asks Jill for a strange favour, Jill finds herself entering a world of mystery and fear.
The stories in the headlines are becoming true, and the shadow of AIDS enters their lives. But Ritchie’s denial is ferocious, and Jill becomes trapped in a world of lies, unable to tell the truth as the situation gets worse.
The Pink Palace flatmates start to find their place in the world: Ritchie (Olly Alexander) is auditioning and falling in love, Jill (Lydia West) has been cast in the chorus of a successful musical, Colin (Callum Scott Howells) is promoted at the photocopy shop, and when Roscoe (Omari Douglas) wakes up in extraordinary surroundings, he sees a way to make his whole life better.
But then the terror they’ve been avoiding suddenly strikes at the heart of the gang, in the most unexpected way. Reeling from the news, everyone has to rally round. And when a hospital takes shocking action, the friends must fight like never before.
Ritchie and Jill hatch a scheme to buy the Pink Palace, and Ash (Nathaniel Curtis) finds himself battling Clause 28, while Roscoe (Omari Douglas) hopes that his secret lover can take him far away from his ordinary life. But secrets are being kept, and Ritchie knows that he’ll have to come out to his parents.
A lonely journey home to the Isle of Wight turns into a dark night of the soul when Ritchie has to confront certain truths. Back in London, the protests against the government’s handling of the AIDS crisis begin. Jill puts herself in danger from the police, and Roscoe’s set on a collision course with none other than Margaret Thatcher – an encounter that neither will ever forget.
As the situation darkens, life inside the Pink Palace is bound by love and compassion, and all the flatmates try their best to help. Jill (Lydia West) and Roscoe (Omari Douglas) work extra hours, while Ritchie (Olly Alexander) clings to past success, and even Carol (Tracy-Ann Oberman) finds a kinder side. But time is running out. And the truth must be told, no matter what the cost. As the final days of the old gang unravel, everyone must face up to the spectre of AIDS and the prejudice and fear that walk alongside it. But when Valerie (Keeley Hawes) goes on the warpath, terrible confrontations are made. It’s up to Jill to find hope and reconciliation for Ritchie in the darkest days of their lives.
The full boxset of It’s a sin is on All4 right now or can be watched weekly 9pm on Friday, Channel 4.