In 1913 Houston, young Howard Hughes learns to spell “quarantine” from his mother amid a cholera outbreak. By 1927, Hughes is directing “Hell’s Angels” and hires Noah Dietrich to manage his business. Obsessed with realism after “The Jazz Singer,” Hughes decides to convert his film to sound, but remains dissatisfied and recuts it post-premiere. He becomes romantically involved with Katharine Hepburn, who helps with his OCD and germaphobia.

In 1935, Hughes sets a speed record with the H-1 Racer and later circumnavigates the globe in four days. He buys a majority stake in TWA. Rival Juan Trippe and Senator Brewster introduce a bill to give Pan Am international exclusivity. Hepburn leaves Hughes for Spencer Tracy, and Hughes has relationships with Faith Domergue and Ava Gardner while still loving Hepburn, bribing a reporter to keep their affair secret.

In the mid-1940s, Hughes works on two military projects. In 1947, he crashes the XF-11 during a test flight, survives, and continues developing the H-4 Hercules with his own funds. His OCD worsens, leading to paranoia and surveillance of Gardner. The FBI investigates his finances.

Brewster offers to drop charges if Hughes sells TWA to Trippe, but Hughes refuses. He retreats into isolation, then emerges to defend himself in a Senate investigation, accusing Brewster of bribery. He vows to complete the H-4 and threatens to leave the country if unsuccessful. After flying the H-4, Hughes begins planning a new jetliner but suffers a panic attack and hallucinations. He recalls his past and repeats “the way of the future.”