Set during WWII in Los Alamos, New Mexico, secrets dominate every facet of family and professional life as scientists Frank Winter and Charlie Isaacs compete to create the world's first atomic bomb.

Frank's attempt to save his team brings seriousconsequences. The scientists' wives find creative ways to survive on The Hill.

The community reels after losing a member, while new security measures affect the scientists' work.

A high-profile guest shakes things up on The Hill. Frank is haunted by his past.

When Babbit's past comes back to haunt him, Frank clashes with Charlie to protect his mentor.

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