Twenty-year-old JoEllen Marsh goes in search of the sperm donor father she only knows as Donor 150. JoEllen has always known that her family was not like other families. She grew up in Pennsylvania with two mothers and one was of the first generation of test-tube babies. When she discovers an on-line registry that connects donor-conceived children, JoEllen turns to the Internet to track them down. As her family tree begins to grow with dozens siblings across the country, JoEllen decides that it is finally time to seek out Donor 150.