'Haven't they grown 'is a story of two seemingly average women. Having ben friends at university they then both get married and have children. But the friendship abruptly ends after the birth of a 3rd child for Flora and Lewis. 12 years later Beth sees someone who looks exactly like Flora and her two kids Thomas and Emily but they still like 2 small children that haven't aged at all. Beth becomes obsessed with figuring out what is going on and as when she thinks there must be a logical explanation another detail in the story proves to her it's not. This book is impossible to put down, what at first sounds far fetched soon becomes more and more possible. In the end I didn't believe anyone and anything . There is a very good twist and the end all in all it's a very gripping story well thought out and written.