Nate discovers that thanks to the Nazi serum, he can transform his skin into steel. However, in his first training session, he accidentally blasts himself and Ray out of the ship... and into 1641 Japan. Meanwhile, Jax and Martin discover a hidden compartment in Waverider and a cryptic message from a friend.

The Legends trace a temporal aberration to the White House in 1987 and discover that Darhk is trying to obtain a rare item. Amaya teams up with a former JSA teammate, while Martin tries to convince his younger self to pay more attention to his wife before it's too late. Meanwhile, Mick has second thoughts about making Ray the new Captain Cold.