There Will Be Blood

Director Paul Thomas Anderson was originally struggling with a script about fighting families when he found a copy of Sinclair’s 1927 novel. Drawn to the cover illustration of a California oilfield, he realized the book’s first 150 pages provided the perfect "stepping-stone" for a story about the ruthless independent oilmen of the early 20th century. However, the film is far from a faithful adaptation; Anderson stripped away the book's later political focus to center on the obsessive, singular drive of his protagonist.

To ground the fiction in reality, Anderson researched real-life oil barons like Edward Doheny and integrated historical artifacts into the script. Even the film’s most famous line—"I drink your milkshake!"—was adapted from 1920s-era Congressional testimony regarding the Teapot Dome scandal. By blending Sinclair's prose with museum research and the cinematic DNA of John Huston’s The Treasure of the Sierra Madre, Anderson created a "period drama" that feels more like a psychological horror film.

At its core, the film is a collision between two types of "prophets": Daniel Plainview (the oilman) and Eli Sunday (the preacher). Critics view this as a biblical parable regarding America’s inability to reconcile greed with faith. Plainview represents the raw, destructive force of capitalism—a man who views every human interaction as a competition to be won. He adopts a son not out of love, but to use him as a "family man" prop to deceive investors.

Eli Sunday serves as the mirror image of Plainview’s corruption. While Plainview uses oil to gain power, Eli uses the pulpit. Their relationship is a cycle of mutual humiliation, culminating in the film’s final scene where the two forces finally consume one another. The "milkshake" metaphor serves as the ultimate indictment of this era: a system where "drainage" is the only goal, and the winner is simply the one who can maneuver their straw the furthest into someone else's reservoir.

The film’s intensity is anchored by Daniel Day-Lewis, who spent years preparing for the role by studying the letters of laborers and the speech patterns of director John Huston. His commitment was so physical that he actually broke a rib during a fall while filming. This level of intensity allegedly contributed to the film's most significant production change: two weeks into shooting, Anderson replaced the original actor playing Eli Sunday with Paul Dano (who was already on set playing Eli's brother).

Dano had only four days to prepare for a role that had suddenly expanded from a bit part to the film’s primary antagonist. Because he had to play twin brothers, the production had to re-shoot two weeks of footage. This pivot created the legendary screen chemistry between Day-Lewis and Dano, characterized by a genuine, unrefined tension that mirrors the escalating hatred between their characters.

While the performances are the focal point, the film’s atmosphere is dictated by its technical "facets"—specifically Elswit’s cinematography and Jonny Greenwood’s score. The music, composed by the Radiohead guitarist, eschews the traditional swelling strings of a period epic in favor of jagged, dissonant orchestral pieces. This choice keeps the audience in a state of constant unease, reflecting Plainview’s internal paranoia rather than the external beauty of the landscape.

Upon its release, the film was immediately recognized as a landmark achievement. It received eight Academy Award nominations and is now frequently cited by critics as one of the greatest films of all time. It is regarded as Paul Thomas Anderson's "magnum opus," not just for its scale, but for its uncompromising look at the "vanishing American frontier"—a place where the foundations of modern industry were built on isolation, blood, and the wreckage of the family unit.