Louis 'Fritz' Fedowitz

 a scientist working for the implosion team in the Manhattan project. A genuine nice guy, Fritz is obsessed with superheroes and science fiction of the era.

Description
"LOUIS “FRITZ” FEDOWITZ is a member of Frank’s team – he is funny, nervous and sentimental."

- Official description

Character overview
Fritz works as part of the small implosion team. He is often seen discussing scientific scenarios based on characters in comics and sci-fi. After the group gets a sample of plutonium, Fritz accidentally swallows it.

Fritz falls in love with Jeannie, an army woman who sleeps with men for money.

Fritz and Jeannie marry in Season 2 and are planning to have a child. However, Fritz is secretly concerned about how the radiation from the plutonium he has ingested would affect Jeannie's pregnancy and a possible child and makes excuses in an attempt to postpone their efforts. Fritz shares his concerns with Jim Meeks, who encourages Fritz to be open and tell Jeannie about his fears.

On the night of Jim's play, Fritz comes with Jeannie to support their friend. But Jeannie has just found out that Jim is a Soviet spy. She confronts Jim about this at the intermission, then leaves in shock. She is murdered by Nora, the other Soviet spy.

Fritz is plunged into a deep depression over Jeannie's death. Nothing anyone says or does can help, until Liza Winter tells him that work will help with his grief and he comes to see that she is right.

Just as Fritz is returning to his old self, Jim reveals that Jeannie was murdered because Jim is a spy and she discovered this. Fritz grabs Jim's gun and is about to shoot Jim when the Trinity bomb goes off. As the light of the atomic weapon engulfs them, Fritz turns the gun on himself and commits suicide.