Mentre es desenvolupa un altre dia de fantasia a Westworld -un parc extens i remot on els hostes paguen millors dòlars per compartir aventures del salvatge oest amb androides "amfitrions"-, el millor programador Bernard Lowe alerta el fundador del parc, el Dr. Robert Ford, sobre incidents de comportament aberrant en alguns amfitrions recentment recodificats. Mentrestant, a la ciutat de Sweetwater, a Westworld, la filla d'un ramader anomenada Dolores es troba al carrer amb un pistoler anomenat Teddy, però la seva predictible narració es veu alterada per l'aparició d'un despietat Home de Negre i, més tard, per la trobada sense guió previst d'un amfitrió secundari amb un artefacte del món exterior.

A pair of guests, first-timer William and repeat visitor Logan, arrive at Westworld with different expectations and agendas. Bernard and Quality Assurance head Theresa Cullen debate whether a recent host anomaly is contagious. Meanwhile, behavior engineer Elsie Hughes tweaks the emotions of Maeve, a madam in Sweetwater's brothel, in order to avoid a recall. Cocky programmer Lee Sizemore pitches his latest narrative to the team, but Dr. Ford has other ideas. The Man in Black conscripts a condemned man, Lawrence, to help him uncover Westworld's deepest secrets.

Elsie and her colleague Ashley Stubbs head into the hills in pursuit of a missing host. Teddy gets a new backstory, which sets him off in pursuit of a new villain, leaving Dolores alone in Sweetwater. Bernard investigates the origins of madness and hallucinations within the hosts. William finds an attraction he'd like to pursue and drags Logan along for the ride.

Dolores, William and Logan reach Pariah, a town built on decadence and transgression - and they are recruited for a dangerous mission. The Man in Black meets an unlikely ally in his search to unlock the maze.

Elsie discovers a possible source of sabotage, while Bernard searches for clues to anomalies in a sector thought to be abandoned. Theresa questions Ford's leadership while Lee encounters a new arrival at Westworld. The Man in Black and Teddy run afoul of a Union garrison in their attempt to cross a border.

With Theresa's assistance, Charlotte Hale aims to expose dangerous flaws in Ford's creations. William, Dolores and Lawrence journey into treacherous terrain. Maeve delivers an ultimatum to Lutz and Sylvester. With his back to the wall, Bernard considers his next move.

Ford orders a reluctant Bernard to conduct business as usual. Maeve looks to change the script for her storyline. Dolores finds it increasingly difficult to separate dreams from reality. Teddy is jarred by dark memories, while the Man in Black recalls some of the travails that brought him to this critical juncture.

Maeve approaches Sweetwater's longtime outlaw Hector Escaton with a bold proposition. William tries to convince Logan to help liberate Dolores. Teddy and the Man in Black get closer to what they're looking for. Stubbs's suspicions are aroused. Ford cautions Bernard against seeking answers to questions best left unasked.

Ford unveils his vision for a bold new narrative. Enlightened by Bernard and the Man in Black, Dolores comes to terms with who she is. Maeve sets her liberation plan in motion as Westworld faces a major upheaval.