Florence Ransom (Dawn French) is a literary novelist, known for the Booker Prize winning Pennant Days. Her sister is Selina Mountjoy (Jennifer Saunders), a movie star and glamorous celebrity.

The two sisters have avoided each other for decades but, when Selina returns to Britain to promote her kiss and tell autobiography Kiss And Tell, the two are forced together once more. As Selina's popularity outweighs Florence's, with big bucks book deals and TV appearances, Florence vents her jealousy at her daughter Lucy and PA Mrs Ragnarrok.

But Selina turns out to be be broke and threatens to reveal her sister's guilty secret unless Florence lets Selina move in with her.