It's Lip's 18th birthday and there are a few surprises in store for him and the rest of the Gallagher family. First, the Maguires move in next door in an attempt to drive a wedge between Mandy and Lip. And, second, mum Monica returns, claiming she is back for good and only Carl welcomes her back with open arms. Annoyed by her estranged mother's sudden return, Debbie calls upon Norma, Monica's lover, for help. Meanwhile, Sue, Kev, Veronica, and Marty plot to buy a Romanian baby. However, Kev and Veronica end up behind bars, while Marty becomes a fugitive. Elsewhere, Sheila is away on a cookery course, and Frank drunkenly burns down her kitchen and ends up in hospital. Once released, he is shocked by the changes that have occurred back on the estate and finds himself in a tricky situation when Monica makes it clear why she has returned. And Stan has a new sidekick - Irish youngster PC Tom O'Leary (Michael Legge).