Siobhan Finneran

Sisters Cat and Cathy reel from the news they have a secret brother, Callum-whom Cathy just snogged. Cat's mom, Marilyn, is furious to learn she wasn't Colin's only mistress and sets about tracking down his other secret lover, Angela. Meanwhile, Cathy's mom, Tess, decides to have some fun with her late husband's legacy and embarks on an ill-advised luxury spending spree.

Cathy is excited to take Cat and Callum to help Auntie Dawn with lambing season on her farm, but the special trip seems ruined when Tess turns up with an unwelcome visitor. The fallout from Cathy's date with Eamon Hammond leads to a rift between the sisters. Will Marcus see an opportunity to win back his ex-fiancée, or will he be too distracted by his attempts to out-man Callum?

As Valentine's Day approaches, Cathy accompanies Cat to her evening math class and is delighted to see the teacher, Eamon Hammond, is a hotty. But as she lets her heart rule her head, there's growing tension between the sisters. Angela resorts to kidnapping her own dog in an effort to win back her husband, Peter, and Tess starts a new job in the worst place possible.

At the age of 10, two troubled and emotionally confused young boys drag a like-aged girl under a bridge and murder her. Brought to trial and known only as Boy A and Boy B, they are locked up by society for their heinous crimes for as long as the law allows, and the media spurns them as vicious monsters. Years later, Boy A is released from prison and looking for a new start. Now he is Jack, and in this new identity tries to integrate himself into a...

The Great War rages across Europe, and not even the serene Yorkshire countryside is free from its effects. The men and women of Downton are doing their part: heir Matthew Crawley and footman Thomas Barrow are off fighting, while Lady Grantham and Isobel Crawley are squabbling over whether Downton should be used as a hospital. Lady Mary is seeing a wealthy newspaper magnate while Lady Edith becomes much warmer and Lady Sybil seeks to ingratiate herself...

Cathy boxes up her father's things in preparation for selling the house, and Cat and Marilyn go overboard taking mementos. Later, Cathy teaches Cat how to ride a bike, while Marcus visits the dump.

When family man Colin suddenly dies, his wife, Tess, and daughter, Cathy, get an even greater shock: Colin had been hiding a mistress, Marilyn, and another daughter, Cat, across town. Two weeks after the funeral, Cathy attempts to retrieve Colin's ashes from his other family, while Tess decides it's time to get back into the dating game.

With the wedding canceled, Marcus has taken his secretary on the honeymoon trip that Cathy planned. To cheer Cathy up, Cat takes her on their own sisters' honeymoon on the boat, and Tess and Marilyn finally sort out Colin's will.

The police appeal for the safe return of Jonjo, with DCI Smilie insistent that the young man's disappearance is not linked to the murder. But when Albrighton informs the press that there may be a serial killer at large, the town erupts into chaos. Meanwhile, Evie grows suspicious of Dr. Marr.

A frustrated Quigley fires Albrighton, but he warns her that the killer isn't finished. Evie continues her search for answers about Dr. Marr's involvement with the McGrellish family, and while following new evidence, Annie finds herself in a race to track down a suspect before more people die.