When Fiona Gallagher's (Anne-Marie Duff) bag is stolen on a night out in Manchester, a handsome stranger called Steve McBride (James McAvoy) comes to her rescue. He accompanies her to her home in Chatsworth, a deprived inner city council estate, to meet her large family, and the pair begin to grow close, until she receives a visit from the police concerning her alcoholic father, Frank (David Threlfall). Meanwhile, Lip Gallagher (Jody Latham) makes a shocking discovery about his brother Ian (Gerard Kearns) that turns the brothers close relationship upside down, and he also uncovers a shocking secret about the local shopkeeper, Kash Karib (Chris Bisson). Elsewhere, Karen Jackson's (Rebecca Atkinson) father, Eddie (Steve Pemberton), leaves home after catching her in a compromising position.

After Karen's father Eddie attacks Frank in The Jockey, Frank returns home and attacks his son, Ian, and Fiona's boyfriend, Steve. Certain he's got a family he doesn't deserve, a vengeful Steve kidnaps a drunken Frank and dumps him in France without telling anyone. While Frank lands himself in trouble with the French authorities, a body is found in the canal at home, and everyone assumes it is Frank. Will the feckless patriarch ever make it home? And how will Fiona react when she discovers what Steve has done? Meanwhile, Karen's agoraphobic mother, Sheila Jackson (Maggie O'Neill), finds a new man, Kev (Dean Lennox Kelly) and Veronica Ball (Maxine Peake) fall out over money, and a local copper PC Tony (Anthony Flanagan) has fallen in love with Fiona.

It's Friday night in The Jockey, and barman Kev says he is getting married to his longtime girlfriend, Veronica, in order to deter the advances of a group of ladies. However, Frank overhears and announces it to the entire pub... including Veronica's mother, Carol Fisher (Marjorie Yates). In a corner, Kev proposes to Veronica, and the pair plan a wedding on the cheap with the help of the Gallaghers, but Kev has failed to tell Veronica that he is already married and turns to Steve and Fiona for help. Even worse, Veronica's arsonist brother, Marty Fisher (Jack Deam), has escaped from prison. Meanwhile, Ian is forced into hiding after turning down the advances of Mandy Maguire (Samantha Siddall) - most popular girl in school and only daughter of the toughest family on the estate - feeling humiliated, she spreads lies and sends her brothers after him. When Lip and Kash are caught in the crossfire, Ian has to decide whether to flee Chatsworth for good or admit the truth about his sexuality.

Debbie Gallagher (Rebecca Ryan) takes a young child, Jody, from his birthday party and dresses him up as a girl. With Frank's assistance, the Chatsworth residents join forces en masse in order to find Jody. The Gallaghers are horrified by Debbie's actions and now face the impossible task of returning the child home without incriminating themselves. Meanwhile, Karen is on a mission to seduce her mother's boyfriend - who is also her boyfriend's father, whilst Veronica has got a new hairstyle.

Frank continues his passionate affair with Karen, even though she is dating his son, Lip, and he is dating her mother, Sheila. Things begin spiralling out of control when Steve discovers the affair, and the penny finally drops for Lip when she dumps him, leading to a violent showdown between him and Frank. Meanwhile, Yvonne Karib (Kelli Hollis) discovers Kash is having an affair with Ian after watching the shop's CCTV footage, but they are both shocked by her reaction. The Gallagher boys parents' evening throws Fiona into a panic, while Veronica goes to saucy lengths to pay off her catalogue debt.

Bailiffs reclaim old debts from Frank, and, as usual, his children are forced to pay the price. If that isn't enough, Mr. Wilson (Clive Russell), a housing officer with a personal vendetta against Frank, is threatening to take the family home. Frank, however, is busy trying to get money out of his ex-wife, Monica Gallagher (Annabelle Apsion). With Kev's assistance, Frank manages to fool Monica, but he makes the mistake of letting her know he is after her. The pair are chased back to Chatsworth by Monica and her lesbian lover, Norma Starkey (Dystin Johnson), leading to a rollercoaster of emotions within the fractured family. Meanwhile, Tony's love for Fiona reaches new depths when he asks her to marry him.

Monica and Norma are ruling the roost at the Gallagher household after Fiona moves in with Steve, but none of the Gallagher kids are happy by their mother's return. Frank is desperate to make contact with his estranged wife, but first, he must deal with his growing debts, two debt collectors watching his every move, the threat of homelessness for his entire family, and Monica's aggressive girlfriend, Norma. However, it's his new rival Norma who comes up with the perfect solution: fake his own death so his debts die with him, but Monica and Norma may have an ulterior motive for offering to help. Meanwhile, Sheila tries to overcome her agoraphobia with Debbie's help, whilst harbouring a life-changing secret, and it seems Steve's days as a free man are numbered when a jealous Tony discovers the source of his fortune.