Oppenheimer met his wife, Kitty, during a party in August of 1939, and his relationship with Jean had fallen apart by the end of this year. So the breakup scene between them in the film is very plausible. But as we see in the movie, their relationship did not end there. They continued to see each other about twice a year between their breakup and 1943; as Oppenheimer later explained, “we had been very much involved with one another, and there was still a very deep feeling when we saw each other.” Their reunion in June of 1943, during his return trip to Berkeley from Los Alamos, happens as depicted in the film, and was documented extensively by military agents who shared their findings with the FBI. The agents weren’t in the room to see the two naked, of course, but reported that “the relationship of Oppenheimer and Tatlock appears to be very affectionate and intimate.”
Oppenheimer was under “near-total surveillance” during his time at Los Alamos, with the government never letting go of their suspicions about his Communist ties. After this visit with Tatlock, that surveillance extended to her too. On September 1, 1943, J. Edgar Hoover himself wrote a memo recommending that her phone be wiretapped because she had become “the paramour of an individual possessed of vital secret information regarding this nation’s war effort.” Unlike Oppenheimer, she had not given up her Communist ties at this point. But after months of wiretaps the FBI had learned “nothing to confirm their suspicions that the young psychiatrist was Oppenheimer’s (or anyone’s) conduit for passing information to the Soviets,” as biographers Kai Bird and Martin J. Sherwin write.
Given her brilliance and connections to some of the brightest minds of her era, Jean Tatlock could well have become someone we know as much about as Oppenheimer. Instead, her life ended suddenly on January 4, 1944. As depicted in the film, Tatlock was found lying on a pile of pillows with her head submerged in the bathtub. Her father, Professor John Tatlock, found her, and in an indelible image described in the book, lay her body on the sofa while he went through a stack of her letters and photographs, then burned them in the fireplace.
Tatlock’s death was ruled a “suicide, motive unknown.” She had ingested a number of drugs and left a note that read, in part, “I think I would have been a liability all my life—at least I could take away the burden of a paralyzed soul from a fighting world.” In American Prometheus, the authors speculate she may have been struggling with her sexuality at the time, telling a friend before her death that in order to overcome her attraction to women, she had “slept with every ‘bull’ she could find.” When told the news, as seen in the film, Oppenheimer took “one of his long, lonely walks high into the pines surrounding Los Alamos.”
In the film we see Tatlock’s death in snippets many times, seemingly from Oppenheimer’s imagination. Sometimes she slowly, methodically lowers her head in the bathtub; a few other times we see a black-gloved hand pressing her down as she struggles. That’s a nod to the lingering uncertainty some have about whether Tatlock’s death really was a suicide. One of the drugs in her system, chloral hydrate, is the active ingredient in a “Mickey Finn,” exactly what you would administer to someone if you wanted to knock them out cold. As one doctor says in American Prometheus, “If you were clever and wanted to kill someone, this is the way to do it.”