DI Sheridan Holler is used to solving crimes on Liverpool’s streets, but after a decayed corpse turns up in a cemetery, she finds herself reopening not one but two cold cases. Seven years earlier, two women were gunned down and the only suspect, small-time drug dealer John Lively, was never seen again. Case closed. Until the body in the cemetery is identified as his.

It’s been fifteen years since Gem’s eight-year-old daughter Sara-Jane went missing, snatched with her best friend Abby right outside their school. A frantic search united the community at first, but after Abby was found and brought home, single mother Gem’s dogged persistence only led to accusations that she was stirring up class tensions. Even that she was somehow involved.

Fifteen years ago, a serial killer was on a rampage murdering young women in Middlehampton. Then, suddenly, the killings stopped, and the murderer was never found… So when the body of another young woman is found bearing the twisted killer’s unique hallmark—the overpowering stench of lavender and an origami heart—DS Kat Ballantyne knows this can only mean one thing: the killer is back.

Forensic psychologist Callum Kilkenny lost his wife, Shay, to the very serial killer he’d hunted for five years. When Nathaniel Conrad—known as the Alphabet Man, for his love of tattooing codes onto his victims’ bodies—was condemned to death row, Callum thought the game of cat and mouse was over. But just before execution, Nathaniel drops a bombshell: he’s not the one who murdered Shay.

Everyone in the small town of Denton is searching for Isabelle Coleman, a missing 17-year-old girl. All they've found so far is her phone and another girl they didn't even know was missing. Mute and completely unresponsive to the world around her, it's clear this mysterious girl has been damaged beyond repair. All Detective Josie Quinn can get from her is a name: Ramona. Currently suspended from the force for misconduct, Josie takes matters into her own hands as the name leads her to evidence linking the two girls.