The Gallaghers' return for a fourth series, and its Lip's 18th birthday but not all is going to be clean sailing as there’s a few surprises ready to hit him. First the Maguires expect him to do something for them. But the biggest shock of all is his long-lost mother Monica turning up out of the blue with a bombshell that could turn their lives upside down.

Frank’s desperate to keep the fact that he’s still married to estranged wife Monica from Sheila, and Monica’s not making it easy for him. But Sheila can see that she has competition for Frank and sets about trying to reunite Monica with her estranged lesbian lover. But is Monica still a lesbian?

Monica manages to seduce Frank and sink her claws back in, but he dare not tell Sheila that he and Monica have been sleeping together. Sheila proves to be a frightening adversary when scorned and Frank could be in real danger. But neither Sheila nor Monica want to share him and he has to decide on which wife he wants. But who will he choose?

Ian gets more than he bargained for when a new person enters his life. Another death in the Maguire household causes Mimi to think the family may be cursed.

Debbie's glad to have her dad back at home, but Monica's not happy with all the attention Frank is giving her and tells her it's time she found herself a boyfriend. Also Ian catches the eye of someone he least expected.

Carl wants his family back together and that means getting rid of Norma - for good. Unfortunately, things don't go to plan when Norma proves to be a very tough adversary. Frank agrees to work on Shane's ice cream van - the Maguires use it as a cover for dealing and Frank's got E's on tap! However, there's trouble brewing.

Explosions across the estate spark fears that Chatsworth is a terrorist target. But it has the Maguire's worried that they're under threat from folk a little closer to home when Patrick finds the family semtex missing. Meanwhile when Frank reveals to Monica she was never his first choice over Sheila, Monica vents her anger by turning to Norma for gifts and goodies.

Learning of the death of his three ex-cell mates is sending Paddy round the bend. With the three of them taken out one-by-one in suspicious circumstances, could this mean he's next in line?

An emergency visit to the hospital results in Frank receiving devastating news, prompting him to embark on an orgy of drink and drug-fuelled mayhem, which culminates in a bizarre, drug-induced encounter with his younger self. Elsewhere, Lillian comes up with a surprising way to make money, and Lip's shady past catches up with him and leads to a no-holds-barred fight in The Jockey, with shocking consequences.

Mimi is forced to confront her deepest insecurity after an ex-boyfriend makes a cruel comment about her weight, and Paddy's inability to back up her up forces a wedge between the loving couple. And Carl takes offence when Ian becomes romantically involved with his teacher, ruining his chance at wooing a promiscuous fellow pupil.

Monica seeks to make up for lost years with her children after failing a pregnancy test. Paddy is livid after the Jockey is robbed before Mimi's surprise birthday party, leaving Karen with the responsibility of arranging the bash from scratch. Stan becomes smitten when his pen-pan from the Ukraine pays a visit, but Carrie suspects that the charming foreigner has an ulterior motive.

Frank Gallagher has won the lottery; or so the residents of Chatsworth think when Yvonne announces it on the local news. And Frank's not about to announce that he's never bought a lottery ticket in his life when free drinks are coming his way. But will he 'fess up when Liam is kidnapped and the ransom fee is his so-called winnings?

With the local council doling out money to the new young-mayor, Debbie sees a chance to buy hens and potatoes and give Chatsworth free egg and chips. Meanwhile, Shane falls for his perfect woman and it looks like she's fallen for him but when she takes him back to her place, the spare room at Lillian's; Shane's in for a bit of a surprise. Also, Yvonne has trouble with some yobs in the shop and things get a bit heated has she finally met her natch? And,when Stan runs down an old lady, he confides to Tom and Carrie that he should be wearing spectacles. To save his job, Carrie takes the rap, but when the old lady decides to sue, it might be Carrie who is going to get fired.

A mishap with baby Katie and a bag of Es leads to a standoff between Mandy and Frank. When the family back Mandy, Frank is forced to leave the house and ends up sleeping rough. Meanwhile, when Liam learns he's going to be nappy changing for Monica's new baby, he decides to run away. He catches up with Frank and the two outcasts bond over a camp fire and a leaky tent. Micky's attempts to get into his dad's good books go horribly wrong when he accidentally loses the weekly drug pick-up distracted by a hot guy from the local abattoir. He enlists Ian's help to get them back and the two lads go on an epic search until Ian gets caught by the thieves and Micky has to decide whether to save his friend or his own skin. Shane is delighted when Kellie finally admits that she loves him and he invites her round for Sunday lunch with the family. But Paddy is not happy about sitting round the table with a prostitute and decides to pay Kelly a little visit...

When there is a gas leak at the Gallaghers along comes a sexy fireman named Sean. He gets the attention of Ian and Mandy but which one of them will win the race to get the Sean into bed? Also, Carl finds himself in a risky situation.

On the bus to a re-start course, Frank has the briefest encounters with a beautiful stranger. Debbie invites some members of the church to stay, but has she got an ulterior motive. And Lillian's assigned to a witness protection programme.

Monica has an unexpected visitor, her mother Joan, who no one's seen for twenty years. Suddenly all Monica's childhood insecurities come flooding back. But Joan has a secret, she's got Alzheimer's disease and has a very important task for Monica but, she can't remember what it is. When Stan confesses to Yvonne that he's got a soft spot for her he gets a little more than he bargained for, in the stock room, up against the shelves and behind the frozen goods. Yvonne is a woman with physical needs but does she want this to go any further because, Stan certainly does. When Paddy and Mimi take a holiday, Shane and Mickey decide to throw a party. The only problem is, they've no cash to buy booze and drugs and when they enlist Liam to help them with a money making business venture, they soon find themselves outsmarted.

Jamie's ex-cellmate Mark comes to stay, but Karen doesn't trust him and the battle lines are drawn. Karen's got a fight on her hands if she's to prevent Mark from leading Jamie back into a life of crime. When Carl gets poor grades in his GCSEs, he realises everybody thinks he's a failure. So he sets out to prove them wrong and, with a little bit of help from Paddy, finds his real talent in the boxing ring. Yvonne gets a shock when she hears that her daughter Meena has arranged her own marriage. Meanwhile, Norma finds herself on a date. But is she over Monica yet?

When Paddy is caught on camera for an armed robbery and could face 20 years inside, Mimi begs him to call his brother, Noel. He's the only one who can help. But Paddy has a dark history with his sibling and would rather go to jail than ever set eyes on him again. As the reality of his situation dawns, he realises he has no choice. The Gallaghers find themselves three grand in debt to Mimi after Frank inhales a box of her drugs, and it seems that Ian is the only one who can bail the family out. But when his business venture fails, Ian finds he has nowhere to turn. In an act of desperation, he steals money from the till at the Jockey but things quickly spiral out of control. The status quo gets altered in the police house when Carrie becomes a sergeant. Tom is peeved that Carrie is exploiting her new position, but a chance comment leads him to discover a dark secret in Carrie's past, which means he can regain the upper hand...

When Stan gets caught in the crossfire between Yvonne and her kids, a full-blown row puts their relationship on the rocks. Things go from bad to worse when Yvonne finds herself held at gunpoint in the shop. Stan comes to the rescue but any hopes of this leading to an easy reconciliation are thwarted when the gun goes off and Stan lies bleeding amongst the cut-price yoghurts. Monica starts to panic when she discovers that the delivery date for her baby could be sooner than she thought. Faced with the unbearable last weeks of pregnancy and dreading maternal failure, she concludes that the only way through is to face her fears, bring on the birth and get it all over and done with. Carl announces that he's going to join the army. After all, there are some good perks: lots of travel, learn a trade and the girls love a guy in uniform. But can he really put himself up as canon fodder?

Mandy looks set for an upturn in her love life when she's persuaded to go on a blind date by Karen, Jamie and Ian. It seems she's struck gold and is onto a keeper, until her first night of sex and drugs turns into a nightmare. Finding themselves with a corpse on their hands, Karen and Mandy have to work out how to get rid of the evidence before they're charged with murder. It's a long night for the girls as they drag a heavy wheelie bin around the estate...

After Mandy gets arrested for suspected drug running she forms the most unlikely of friendships and finds herself helping Tom search for his real mother. The friendship, however, soon becomes something deeper for Mandy and with the help of Ian, she sets out to win Tom's heart. But do Tom's affections lie elsewhere? Mimi's short fuse gets the better of her when she harms her favourite son, Micky. Desperate to rein in her temper she attends anger management courses and gradually evolves as a new, sensitive woman - and responsible drug dealer. Seeing his business going down the pan, Patrick despairs and knows he has to get his old Mimi back or they'll go bankrupt. In an attempt to impress a new girlfriend, Carl enlists Karen as his personal sex counsellor, but is he getting help or getting off?

While enjoying another secret rendezvous, Debbie and Tom are forced to come to the aid of an assaulted woman, but things go horribly wrong when Tom gets arrested on suspicion of being the attacker. Only Debbie can supply his alibi, but not without putting both of them in a compromising position. There's a gruesome showdown between Shane and Paddy over Shane's girl, leaving Mimi torn between her love for her husband and the love she feels for her son. When Norma wakes up in a stranger's jogging bottoms after a night on the tiles, she sets off on a wild goose chase to find out whoever it was she slept with.

When Manchester experiences an earth tremor, Monica's waters break and she goes into labour. On the other side of Chatsworth, the same tremor knocks Frank off of his barstool and puts him in a coma. Monica's refusing to have the baby unless Frank is present, but how long can she keep her bun in the oven? While he's out cold in his hospital bed, Frank experiences an alternative world: a life where he is a success, where Ian isn't gay and Debbie looks like she'll never leave home. It's the world as Frank would have it; or is it? Carl is finding new success with girls by posing as a single parent. It's all going very well until his latest target runs off with the baby. Meanwhile, Shane has a proposal to put to Kelly.

Ian is attacked and left shaken and confused as to what he could have done to provoke it. When the stranger strikes again, Ian is left hospitalised and there's more bad news when he regains consciousness: he's got amnesia. Suddenly he's an alien amongst his own family and friends, and even his own sexuality is a mystery. Meanwhile it's Debbie's 16th birthday. Tom decides it's time to go public with their relationship, but Debbie has doubts about whether their relationship was ever really serious. Kelly has bad news for Shane about her pregnancy; Frank and Monica are faced with an impossible challenge when they hear the voice of newborn baby Stella: but do they want to know what she has to say about her parents and Chatsworth? And Ian's amnesia brings him a whole new perspective on his life, leaving him questioning if Chatsworth is the place for him after all.