Fifteen-year-old Emma lives with her Mum and Dad in Edinburgh. Her older brother has left home but has a good relationship with Emma and their parents - they are a close, happy family. The arrival of Eve changes everything. Eve follows Emma around and the two girls look a lot alike. Eventually Emma discovers that Eve' is her half sister, conceived one night sixteen years ago, when her father was in London. The story is of a family dealing with a tough and intriguing situation.