Josie, Nell and Lisa go back a long way - they were flatmates, soulmates and best mates back in their twenties when life was one long party. Five years later things are different. Josie is married with kids in deepest suburbia, free-spirit Nell has travelled the world, and Lisa is on the path to career glory. A reunion weekend in London seems a great idea to Josie - until she discovers something which threatens to blow her happy marriage apart.