Frank Winter and his team have been recruited to work on a project even they could know nothing about until their arrival. Once inside "The Hill", a middle class bubble on a dusty foothill in the New Mexico desert, they begin to sense that this is no ordinary assignment. In fact, they are living in a town with the world's highest concentration of geniuses, yet it can't be found on any map, a place where men and women are torn between duty and their moral values, husbands and wives conceal the truth from each other and their families, the military keeps secrets from the scientists they chaperone, and the scientists keep secrets from each other.

A special shipment of the first sample of plutonium arrives at The Hill - one that could change everything. With the future of his team up in the air, Frank knows that having some of the precious material could make all the difference. As Frank desperately tries to keep his team alive, he learns that Liao has been detained by a covert outside party. Meanwhile, Liza helps Abby find creative ways to survive life on The Hill. As the wives grow closer, competition escalates between Frank and Charlie in the lab.

As the news of Sid's passing reverberates through the compound, the base begins cracking down on security on The Hill, which creates new complications for the scientists' work. With all files and case studies on lockdown, Frank's team is locked in an uphill battle to resolve the Implosion experiment without Sid's expertise, leading Frank to resort to creative measures. Meanwhile, Charlie grapples with unsettling feelings about his group and Abby starts a new chapter. Elsewhere, an MP looks for penance for his actions.

Frank grapples with haunting memories from his past and his erratic behavior gets called into question, putting his team's loyalty to the test. Meanwhile, The Hill receives a special visitor in famed physicist Neils Bohr, whose sudden arrival sparks curiosity among the scientists - and Charlie is assigned to escort him around the compound. Elsewhere, Callie plots an escape.

Tensions between Charlie and Frank escalate after Charlie takes a public jab at Babbit's past, raising red flags and drawing the attention of Occam - leading Frank to find creative ways to protect his mentor. Meanwhile, Liza suffers several blows of her own - and points the finger at the army.

When Charlie is chosen to go on an important trip to Tennessee to see the country's first plutonium reactor, tensions in the Isaacs' marriage only deepen when Abby learns that Charlie is accompanied by Helen on his trip. Back on The Hill, Fritz has a medical emergency - and Frank's attempt to intervene leads to a shocking discovery.

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

When British scientists who have done extensive work on an Implosion model similar to Frank's visit The Hill, Frank gains some unsettling perspective. Meanwhile, Charlie grapples with whether to tell Akley about the revelation he made about Plutonium, as well as his fate with their group. As Charlie and Frank both face grim predictions about the future of their prototypes, the stakes at home are raised when Abby discovers what is really happening to the Jews in Europe.

A plan is hatched by Frank and Charlie.

A surprise visitor shows up on the Hill.

The spy on Hill becomes invigorated when developments happen overseas.

Akley tries to fix Thin Man's short-coming's and ends up been exposed.

Frank is given a life-changing opportunity; Charlie finds himself in the U.S. Army's hot seat.