Akley becomes vulnerable when he tries to fix Thin Man's shortcomings.

Frank is offered a life-changing opportunity. At the same time, the U.S. Army put Charlie on the hot seat.

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

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.

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

Frank and Charlie hatch a plan.

An unexpected visitor arrives on the Hill.

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.

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

Frank seeks medical answers; Charlie and Helen travel to survey an off-site reactor.

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

Helen and Charlie deal with a crisis; Abby embarks on a journey of self-discovery.

A drama about the clandestine race to build the world's first atomic bomb in Los Alamos, N.M., centers on a self-destructive professor who is commissioned to help lead the Manhattan Project in the series opener.