Fat Man and Little Boy - Basis

Basis

Most of the characters were real people and most of the events real happenings, with some theatrical license used in the film.

The character of Michael Merriman (John Cusack) is a fictional composite of several people and is put into the film to provide a moral compass as the "common man". Part of the character is loosely based on the popular young scientist Louis Slotin. Contrary to Merriman's death in the movie, Slotin's accident and death occurred after the dropping of the two bombs on Japan, and his early death was feared by some as karma after the event; see their respective articles. A very similar mishap happened less than two weeks after the Nagasaki bomb, claiming the life of Harry Daghlian. Both incidents occurred with the same plutonium core, which became known as the Demon core.

Even before Oppenheimer was chosen to be the lead scientist of the Manhattan Project, he was under surveillance by the Federal Bureau of Investigation (FBI), and once selected, the surveillance was intense; every single phone call was recorded and every contact with another person noted. After he was picked to head the laboratory, he only met with Tatlock one time, in mid-June 1943, where she told him that she still loved him and wanted to be with him. After spending that night together, he never saw her again. She committed suicide six months after their meeting.