Paul Dano wasn't supposed to be Eli Sunday. Not originally. When Paul Thomas Anderson started filming There Will Be Blood, the young actor was only cast as Paul Sunday, the brother who sells out his family’s secret for a quick $500. He was basically a bit player. A catalyst. A ghost in the script meant to vanish after the first act. But things got messy on set in Marfa, Texas, and that messiness birthed one of the greatest dual performances in modern cinema.
It’s been nearly twenty years since the film hit theaters, and people still argue about whether Paul in There Will Be Blood and his twin brother Eli are actually two different people or just a psychological projection of Daniel Plainview’s deteriorating mind. Honestly, the truth is way more grounded in the chaos of filmmaking.
💡 You might also like: Why the Great Expectations Cast 1946 Still Defines Dickens on Screen
The original actor hired to play Eli Sunday just wasn’t working out. Rumors have swirled for years that the pressure of acting opposite Daniel Day-Lewis—who was famously "in character" as the terrifying silver-tongued oilman—was too much. After two weeks of shooting, Anderson made a pivot that changed film history. He asked Dano, who had already shot his scenes as Paul, to step into the much larger role of Eli. Dano had four days to prepare.
The Mystery of Paul in There Will Be Blood: One Brother or Two?
The movie opens with Paul Sunday visiting Daniel Plainview. He’s quiet. He’s transactional. He knows exactly what he has: oil. He also knows exactly what he wants: money to start his own life away from his father’s "goat ranch." Paul is the smart one. He exits the frame and never returns, leaving his twin brother Eli to deal with the devil he just invited onto their land.
You’ve probably seen the theories. Some fans think Paul and Eli are the same person—a con artist with a split personality playing both sides of the fence to manipulate Plainview. It's a fun theory, but it doesn't hold up if you look at the screenplay or the source material, Upton Sinclair’s Oil!. In the book, the characters are distinct. In the movie, the distinction is more spiritual. Paul is the materialist. Eli is the "prophet." Both are greedy, but Paul is honest about it.
Why the Sunday Twins Matter to the Plot
If Paul hadn't sold the location of the Sunday ranch, Daniel Plainview might have eventually found oil elsewhere, but he wouldn't have found his perfect foil. Eli Sunday represents everything Plainview hates: organized religion, performative morality, and someone else claiming power over "the sheep." Paul, meanwhile, is the only character who actually "beats" Daniel. He gets his money, he leaves, and he presumably thrives while everyone else in the story ends up dead, drunk, or humiliated.
Think about the contrast in their voices. Paul speaks in a low, steady register. He’s calm. He tells Daniel, "I’ve come to tell you where it is." He’s a businessman. Then look at Eli. High-pitched. Shrieking. Desperate for validation. Dano’s ability to flip that switch with almost zero prep time is why PTA (Paul Thomas Anderson) trusted him to carry half the movie.
The "Daniel Day-Lewis" Factor
Acting is usually a collaborative dance. With Daniel Day-Lewis, it was more like a psychological siege. There’s a famous story—or maybe it's more of a legend at this point—that Kel O'Neill, the original Eli, left because Day-Lewis was being too intense. Day-Lewis has denied this, saying it simply wasn't a good fit. Whatever the case, Paul Dano stepped into a high-pressure cooker.
Daniel Plainview is a man who wants to "drain" everyone around him. He literally tells us he has a competition in him and wants no one else to succeed. When Paul in There Will Be Blood hands over the map, he's handing Daniel a straw. But Eli tries to take the straw back. The friction between Dano and Day-Lewis isn't just "good acting." It's the sound of two different styles of performance clashing. Dano is reactive and fluid. Day-Lewis is a monolith.
How Paul Dano Handled the Sudden Casting Change
Imagine being 22 years old. You’ve just finished your small role in a massive period epic. You’re ready to go home. Then, the director of Boogie Nights and Magnolia pulls you aside and says, "Hey, I need you to play the main antagonist. And you start Thursday."
Dano didn't have time to overthink it. He leaned into the physical differences. Paul is seen in the shadows, wearing a simple hat, looking like a dusty laborer. Eli is draped in black, his face pale and sweaty under the lights of the Church of the Third Revelation. The brilliance of the performance lies in the fact that they look identical but feel completely different. You never confuse the two, even though they share the same face.
The Realism of the Sunday Ranch
The location where we meet Paul—the Sunday ranch—was shot on the McGuire Ranch in Texas. It was desolate. Hot. Miserable. That environment helped ground the interaction between Paul and Daniel. There was no "hollywood" shine to it. When Paul asks for the five hundred dollars, you believe he needs it to escape that dust. It’s a transaction born of desperation.
Misconceptions About the "Milkshake" Scene
Everyone remembers the ending. "I drink your milkshake!" It’s become a meme, a TikTok sound, a joke. But people forget that the ending is the final payoff for the Paul/Eli dynamic. By the time we get to the bowling alley, Daniel is a broken, wealthy husk. Eli comes to him, broken and poor.
Eli tries to sell Daniel on a new "deal," just like Paul did decades earlier. But Eli is a bad businessman. He tries to use the same information Paul already used. Daniel’s explosion of violence at the end isn't just about the oil; it's about the fact that Eli is a pale imitation of his brother. Daniel actually respected Paul's cold-blooded capitalism. He despises Eli’s parasitic "faith."
Why We Are Still Talking About This Movie in 2026
Movies like this don't really get made anymore. It’s a 150-minute character study about a man who hates people. Yet, it remains a pillar of 21st-century cinema because of these nuanced performances. The role of Paul in There Will Be Blood acts as the inciting incident for the entire tragic arc.
- The Script’s Economy: Notice how little Paul actually says. He’s efficient. He gives the coordinates, takes the cash, and warns Daniel about the "seepage."
- The Visual Language: Costumes by Mark Bridges were used to distinguish the brothers. Paul’s clothes are functional. Eli’s clothes are theatrical.
- The Score: Jonny Greenwood’s discordant, screeching strings emphasize the tension that starts the moment Paul enters the frame.
The film explores the twin pillars of American growth: the oil (Paul’s discovery) and the pulpit (Eli’s exploitation). You can't have one without the other. They are two sides of the same coin, just like the characters themselves.
Actionable Steps for Film Buffs and Students
If you want to truly understand the technical mastery of the Sunday twins, don't just rewatch the movie. You have to look at the process.
- Watch the "Oil!" Comparison: Read the first two chapters of Upton Sinclair’s Oil!. It provides a much deeper backstory for the Sunday family that didn't make it to the screen. It explains why Paul wanted to leave so badly.
- Analyze the Blocking: Re-watch the first scene with Paul and Daniel. Look at how Daniel looms over him. Then, watch the first meeting between Daniel and Eli. The power dynamic is flipped; Eli is the one standing on the porch, looking down.
- Listen to the Commentary: Paul Thomas Anderson’s interviews from the 2007-2008 awards season are a goldmine. He talks openly about the "panic" of re-casting and how Dano saved the production.
- Check the Deleted Scenes: There are fragments of more Sunday family interactions that clarify the timeline. While the theatrical cut is lean, the extended lore shows that the brothers were always intended to be distinct entities.
The legacy of Paul in There Will Be Blood is a testament to the "happy accidents" of filmmaking. Sometimes, losing an actor and having to double-cast a genius like Paul Dano results in a layer of subtext that a perfect, planned production would never have achieved. It turned a straightforward story about oil into a haunting meditation on bloodlines and the different ways men sell their souls.
🔗 Read more: Ballad of a Small Player: Why Colin Farrell’s New Netflix Thriller is Dividing Fans
Next Steps for Deepening Your Knowledge
To fully grasp the impact of the Sunday brothers' dynamic, track down the "15 Minutes" making-of documentary included on the special edition Blu-ray. It highlights the location scouting in Marfa and shows the actual ranch house where the Paul Sunday scenes were filmed. Seeing the starkness of that landscape in raw footage makes Paul's desire to escape for a mere $500 feel incredibly visceral and real.