Charlie is forced into a new leadership role in the race to build the world's first atomic bomb.

Frank discovers the real reason he's been taken captive.

Liza faces off against Darrow as Abby learns a secret about Oppenheimer.

Oppenheimer puts Charlie in a precarious position.

Frank attempts to navigate his new place on the Hill.

The scientists and the Army battle for control of the bomb.

The hunt for a Soviet spy turns deadly.

As the project falters, Charlie turns to an unlikely partner for help.

Days before the world's first nuclear explosion, everyone races to secure their place in history.

A new era is ushered in with the first test of an atomic weapon.