Sisters Catherine `Cathy' Walcott and Catherine `Cat' Walcott only discovered one another existed after their dad dropped dead. Cathy has a fiancé, a Duke of Edinburgh Award and a pension. Cat has a pay-as-you-go phone. The only things they have in common are their names. Both of them have always wanted a sister, but perhaps not the ones they ended up discovering. Having finally come to terms with the fact they are sisters, they are now reeling from the news that they also have a brother, Callum, and that Cathy just snogged him.