In 2003, the infant Chinese twin sisters Mia and Alexandra were found in a cardboard box. They ended up in an orphanage and were put up for adoption, at which time the authorities apparently decided that it was a good idea to separate them, and to keep silent about the fact that they were twins. Twin Sisters tells their story from the perspective of both sets of adoptive parents: one from Sacramento, California, the other from a tiny village in picturesque Norway. Through a series of coincidences that they later attribute to fate, the parents meet each other during the adoption procedure in China and launch an investigation that reveals the little girls are sisters.