Dayton, Ohio. February 9, 1979.
A 39-year-old man named Jim Lewis is standing at the door of a stranger's house. The man who opens it is Jim Springer.
He has Jim Lewis's face.
They are identical twins, born in 1939 and separated when they were only a few weeks old. Two families in two different Ohio towns adopted them. Both were told the same thing: their son's twin had died at birth.
It wasn't true. Both babies had lived, and they had grown up as strangers.
Each family named its baby without knowing what the other had chosen. Both chose James. Both boys grew up as Jim.
That was only the first match. Before long, the list would include their wives, their sons, their childhood dogs, their jobs and even the small Florida beach where they spent their vacations.
For 39 years, their lives had run side by side, and neither man had any idea how closely.