The film follows the rise to power of Daniel Plainview (Daniel Day Lewis) a hard working and charismatic oil prospector at the turn of the century who has a has a little kid, H.W..After hitting it big with a well, he moves down to southern California, looking for other prospects. One night a young man by the name of Eli Sunday (Paul Dano), comes to his office telling him he knows of a place with oil where he could drill. In exchange of 500 dollars, he gives Daniel the exact location of the place, where his family's ranch is, in Little Boston, California.

Daniel Plainview goes there to scout the location and senses there is oil indeed to be found. He buys up land and brings his crew. Eli Sunday also turns out to be a religious freak and an antagonism develops between him and Daniel and Eli makes various requests to build his church. Eventually they find large quantities of oil and Daniel Plainview becomes very successful. Success, however, comes with pain as when the derrick blows up, his little kid H.W. has an accident and loses his hearing. One day a man shows up at his door telling him he is his brother Henry, a brother from another father. The two become close and eventually H.W. becomes jealous setting fire to their tent. As a consequence, he is sent away. Eventually Daniel find out Henry is not his real brother, he lied to get close to him and Daniel shoots him.

As Daniel's business grows, they need to build a pipeline through a land that Daniel doesn't own. It is owned by an old man, Bandy, who not only doens't want to help him, but he also know what he did to Henry....He will, however, let him build the pipeline if he joins Eli's church of the Third Revelation and accepts to be baptized, accepting the lord.

This scene takes place at the church. It is serio-comic and grotesque as the scene is actually dramatic but it is awkward as Daniel doesn't believe in God and is only doing it to get his pipeline built. Eli gets him to his knees, scolding him for abandoning his son, lusting for women, making him shout all his sins. He then slaps him as he tries to get the devil abandon Daniel's body before baptizing him....