"Dissonance Theory" is the fourth episode in the first season of the HBO science fiction western thriller television series Westworld. The episode aired on October 23, 2016.

The episode received positive reviews from critics, and in particular to Thandie Newton's performance in the last scene.

Bernard interviews Dolores in Operations about her family's murder. While she experiences pain from it, she does not wish it to go away as it is the only memory of her family, and reminds her something is wrong with the world. Bernard suggests she find the center of the maze to become free.

Dolores wakes in Logan and William's camp. Too far into their bounty hunt to return her to Sweetwater, they continue to hunt down Slim Miller. Passing through Lawrence's village, Dolores has a vision of his daughter, telling her to find the maze. On tracking down Slim, Slim says his boss will double their reward, which Logan recognizes as a rare narrative opportunity and takes it.

The Man in Black and Lawrence find Hector's henchwoman, Armistice, bathing in a river. Seeing a snake tattoo on her body, they recognize her as the next clue, and introduce themselves. Armistice offers to give more information on her tattoo if they help free Hector, held by the local sheriff. The Man goes alone to rescue Hector, and on return, Armistice reveals the tattoo represents the men she had killed in revenge for killing her mother, the only man missing being Wyatt. The Man and Lawrence take their leave. As they continue, they find Teddy tied up. The Man releases him, saying that "misery is all [he] has".

Theresa learns of the stray host and demands the QA department oversee debugging the hosts. She goes to see Dr. Ford, who is overseeing a new excavation on site, to express her concerns about his narrative. He reminds her that her position is easily replaced and knows of her affair with Bernard. He also informs her that his activities have all been approved by the park's board.

Maeve, back in the park, has visions of the people she saw in Operations. She realizes it is similar to figures she had drawn before as well as dolls carried by the children of the native tribes. She waits for Hector's gang to rob the saloon's safe to ask him about the figures and he tells her it is a Shade, a spirit that can cross back and forth to the underworld. Maeve recalls the massacre the day before and purposely stabs her unblemished stomach to pull out a bullet. She passionately kisses Hector as marshalls surround the building.

"Dissonance Theory" was written by Ed Brubaker and series co-creator Jonathan Nolan.