The stranger in my genes

the long version

"Bill Griffeth, longtime genealogy buff, takes a DNA test that has an unexpected outcome: 'If the results were correct, it meant that the family I had spent years documenting was not my own.' Bill undertakes a quest to solve the mystery of his origins, a quest which will shake his sense of identity. As he takes us on his journey, we learn about choices made by his ancestors, parents, and others--and we see Bill measure and weigh his own difficult choices as he confronts the past" -- Publisher's description.