Was the Bay Area’s Jean Tatlock Oppenheimer’s ‘truest love’ or the first casualty of his ambition to build the atomic bomb?

When the blockbuster movie “Oppenheimer” opens July 21, Bay Area audiences will be introduced to Jean Tatlock, one of the most remarkable people to know and love the UC Berkeley physicist, famous as “The Father of the Atomic Bomb.”

The thumbnail version of Tatlock’s life is that she was J. Robert Oppenheimer’s troubled mistress. She also may have been his “truest love,” but her activism in the Bay Area Communist Party in the 1930s threatened his career, both when he was the science director at the top-secret laboratory in Los Alamos, and in the 1950s, when anti-Communist fervor was at its heights and he endured a humiliating grilling by the Atomic Energy Commission and loss of his security clearance.

Tatlock, a Stanford-trained psychiatrist, died tragically by suicide at the age of 29 – some seven months after Oppenheimer drew the alarm of FBI director J. Edgar Hoover by flying back to San Francisco in June 1943 to meet her and spend one final night with her in her Telegraph Hill apartment.

In fact, this final meeting provides a dramatic rendering of Tatlock in Christopher Nolan’s film, though with some details changed. As the original FBI report recounted in cinematic detail, Tatlock met Oppenheimer at the train station in San Francisco. He “rushed” to kiss Tatlock, who was described as slim, dark-haired and attractive. She took his arm and led him to her car. The couple appeared “very affectionate and intimate” as they drove to a Mexican cafe on Broadway for dinner and drinks, then retreated to her top-floor apartment beneath Coit Tower. “At 11:30 p.m. lights went out.”

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In the film, Tatlock is played by the dynamic Florence Pugh, and she and Cillian Murphy, who plays Oppenheimer, filmed prolonged nude scenes to emphasize the love story. Still, Tatlock remains a supporting character in Nolan’s conflicted-great-man-of-history narrative of Oppenheimer, even as biographies of the scientist show that people also saw “greatness” in her.

When Tatlock died, she was on the threshold of a brilliant career, notes “American Prometheus,” the biography by Kai Bird and Martin Sherwin on which the film is based. She was one of the few women of her era to graduate from Stanford Medical School, and she hoped to pioneer psychiatric care for troubled children at San Francisco’s Mount Zion Hospital, then the foremost center in Northern California for training mental health professionals.

In this way, she was one of the “extraordinary” American women of the first half of the 20th century — urbane college graduates who challenged traditional gender roles by having careers and becoming fully engaged in the major social movements of the time, according to Bay Area authors Patricia Klaus and Shirley Streshinsky in “An Atomic Love Story,” their book about the significant women in Oppenheimer’s life.

When Tatlock studied at Vassar in the early 1930s, her classmates included the poet Elizabeth Bishop and novelist Mary McCarthy, whose book “The Group” chronicled the lives of Vassar graduates who similarly expected to be “extraordinary.” Even in such company, Tatlock was still “the most promising girl I ever knew,” a classmate said.

Tatlock was primed for greatness by her father, John Tatlock, a renowned expert in medieval English literature, and her mother, Marjorie, a free-thinking faculty wife who encouraged her daughter’s love of poetry and theater and, later, her interest in radical politics and the burgeoning field of psychoanalysis.

John Tatlock taught at Stanford when Jean was a young girl. He then directed Harvard’s English Department during Tatlock’s early adolescence before moving back west to teach at UC Berkeley when Tatlock was in high school. Even before Tatlock met Oppenheimer in 1936, her father had become friendly with the charismatic physics professor who also possessed a wide-ranging knowledge of literature.

One of the most remarkable things about Tatlock, as revealed in “An Atomic Love Story,” is that she was a beautiful writer. Even as a young girl, she shared her thoughtfulness and intensity in letters she wrote to close girlfriends from Cambridge. The letters radiate an adolescent girl’s excitement about the mysteries of life and love and convey longing for moments of beauty and transcendence.

Some of these letters sound romantic, with Tatlock becoming particularly close to one teenage friend, for whom she confided feelings “love” and “passion.” Biographers note that Tatlock struggled with her sexuality throughout her life. While she told that friend, “I don’t think I’m lesbian,” “American Prometheus” suggests that her professional training in Freudian analysis might have taught her that homosexuality is a pathological condition to be overcome.

Tatlock’s adolescent writing also revealed extreme emotions and vivid imagery – from “ecstatic revelations to painfully beautiful awareness,” according to “An Atomic Love Story.” The language seemed to  “presage the struggles to come,” possibly manic episodes “suffused with velocity and energy until she plunged into depression and despair.”

Tatlock’s emotional turmoil may have prompted her become a psychiatrist, as well as to develop empathy for the less fortunate. Before and after graduating from Vassar in 1935, she became involved in protesting capitalism and supported striking dock workers in Oakland and San Francisco. Once back in the Bay Area, she became a “dues-paying member” of the Community Party and wrote for Western Worker, the party’s Pacific Coast outlet.

Oppenheimer arrived at Berkeley in 1929, a graduate of Harvard, Cambridge and the University of Göttingen. When he and Tatlock met in 1936, at a party hosted by his landlady in the Berkeley hills, he was 32 and a star in the world of science. She was 22 and about to start medical school at Stanford.

Mary Ellen Washburn was a socialist friend of Tatlock’s who was famous for her gatherings of intellectuals and activists. It’s easy to imagine that she nudged her friend to meet her attractive tenant, who would have been “characteristically waving his cigarette in the air as he spoke, keeping the attention of the circle around him,” Klaus and Streshinsky said. He was slender, charming, as well as rich, the son of of a prosperous Jewish immigrant from Germany who had raised him in luxury on New York’s Upper West Side.

It’s likely that Tatlock commanded Oppenheimer’s attention that night. He would been drawn to Tatlock as a “serious woman” who also was good-looking. She was the “one person in the room, whatever the circumstances, who remained unforgettable,” a friend once said.

Oppenheimer didn’t call for a date until he returned to Berkeley in the fall. But as soon as they began seeing each other, he fell fast, according to biographers. He found himself “pleasantly out of control, strangely euphoric” over his feelings for a woman, who was “lyrical, uplifting, sensitive.”

They bonded over the metaphysical poetry of Gerard Manley Hopkins and John Donne and a shared fascination with the potential of psychotherapy. The film also shows Tatlock asking Oppenheimer about his learning Sanskrit, to read the The Bhagavad-Gita, as a form of foreplay. He also didn’t recoil from her “deep depressions,” having survived suicidal despair when he was at Cambridge in his early 20s. “He could not believe that someone as loving and yearning and good as Jean could not be rescued,” Klaus and Streshinsky wrote.

Tatlock’s friends credit her with awakening his social conscience. While Oppenheimer never joined the Communist Party, he worked with her on championing some of the its causes, including the Republicans fighting in the Spanish Civil War. The two became a power couple in Bay Area progressive politics, though Oppenheimer’s activism drew regular warnings from his Berkeley colleague, Ernest Lawrence.

Oppenheimer twice proposed marriage, thinking that Tatlock was young enough to finish medical school and start her career before having children. But their relationship was stormy. They’d break up, and she’d disappear from his life for a time, then they’d reconcile. Friends were never clear about the relationship because they kept it private. Tatlock’s questions about her sexuality could be one reason she rejected his proposals, but Klaus and Streshinksy said she also could have feared that marriage to a prominent man would subsume her identity.

By 1939, their relationship was over. In 1940, Oppenheimer met the vivacious Katherine “Kitty” Puening, who had previously been married three times, including to a hard-core American Communist who died fighting in Spain. When Kitty found herself pregnant with Oppenheimer’s first child, he married her and they set up house in a Spanish-style villa with bay views in Kensington.

Still, he and Tatlock remained “very much involved with one another,” as he was recruited to help with the Manhattan Project. He testified at his 1954 security clearance hearing that there was “very deep feeling when we saw each other,” though he said they only met a few times between 1939 and 1943: at the hospital, at her apartment, on New Year’s Eve in 1941 and for drinks at the Top of the Mark.

After Oppenheimer moved his family to Los Alamos in March 1943, he didn’t see Tatlock before he left. He couldn’t say much about his work and knew she wouldn’t approve. When she begged to see him again, he couldn’t stay away. He said she was in psychiatric treatment, “deeply unhappy” and “still in love with me.”  After they spent their final night together, she drove him to the airport south of San Francisco, where he caught a plane back to Los Alamos.

In the film, Oppenheimer tells Tatlock he can’t see her anymore, while Hoover used their meeting to label her a potential spy and to obtain permission to wiretap her phone.

By New Year’s 1944, Tatlock had fallen into one of her “black moods.” When she failed to call her father as promised on Jan. 4, 1944, he went to her apartment the next day. The professor found his daughter’s body next to the bathtub, as well as a note, on which she had scrawled, “I am disgusted with everything.” She said she had fought “like hell” to live, but feared becoming a burden and said, “At least I could take away the burden of a paralyzed soul from a fighting world.”

John Tatlock made the unusual decision to lay her body on the couch and to rummage through her apartment and burn certain letters and photos before using her phone to summon help. It’s believed that the letters burned were personal in nature.

John Tatlock’s actions were just one of the reasons that questions endure over Tatlock’s death. Her late physician brother, Hugh, and others have wondered about the position of the body, her death by drowning and reports of a sedative found in her system. In addition, Hoover learned of her death almost immediately because of the wiretap on her phone. Her death was addressed in the 1975 Senate hearings regarding covert CIA assassination plots.

For his part, Oppenheimer seemed to accept that she was despondent enough to take her own life and was stricken by grief and guilt that he failed her. He imagined her believing that he put his ambition ahead of his love for her, in a sense making her “the first casualty” of his directorship of Los Alamos, according to “American Prometheus.” Eighteen months later, he oversaw the detonation of the first atomic bomb in the New Mexico desert. He called the test “Trinity,” with film showing that he named it for a sonnet by Donne that she loved, “Batter my heart, three-person’d God …”