Frank attempts to save his team, and pays the price; at the same time, the wives get creative trying to make life on the Hill more interesting.

The loss of one of their own leaves the community reeling; and new security measures interfere with the work being performed by the scientists.

The arrival of a high-profile guest shakes things up. Frank is haunted by his past.

Frank clashes with Charlie to protect Babbit, who has become the subject of an investigation.

Both Charlie and Frank face serious questions as to the future of their projects.

Frank and Charlie hatch a plan.

A development overseas re-invigorates the hunt for a spy on The Hill. Charlie and Abby make a sacrifice when the plan with Frank is threatened.

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

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.