Elyse had always known she was adopted, but it wasn't until her mid-thirties that she searched for her biological mother. She was not prepared for the life-changing news: she had an identical twin sister. Not only that: she and her sister, for a time, had been part of a secret study on separated twins. Paula also knew she was adopted, but had no inclination to find her birth mother. When she answered the phone one spring afternoon, her life suddenly changed. As they take their tentative first steps from strangers to sisters, Paula and Elyse are also left with haunting questions. As they investigate their birth mother's past, they begin to solve the puzzle of their lives. Interweaving eye-opening studies and statistics on twin science into their narrative, they offer an intelligent and heartfelt glimpse into human nature.--From publisher description.