2. The Prisoner's Dilemma

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.

3. The Hive

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

4. Last Reasoning of Kings

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

5. A New Approach to Nuclear Cosmology

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

6. Acceptable Limits

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

7. The New World

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

8. The Second Coming

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

9. Spooky Action at a Distance

Frank and Charlie hatch a plan.

10. The Understudy

An unexpected visitor arrives on the Hill.

11. Tangier

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.

12. The Gun Model

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

13. Perestroika

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