Everyone loves a wedding… and a family row. Three sisters from very different walks of life return to their childhood home to celebrate a momentous event: the third wedding of their twice-widowed mother, Diana (Kristin Scott Thomas). As the weekend unfolds in unexpected ways, Katherine (Scarlett Johansson), a Captain in the Royal Navy; Victoria (Sienna Miller), a Hollywood star; and Georgina (Emily Beecham), a palliative nurse, are forced to reassess their childhood – and make tough choices of their own.