Delos is a futuristic amusement park that features themed worlds—ancient Rome, Medieval times and the Old West—populated by human-like androids. After two patrons have a run-in with a menacing gunslinger in West World, the androids at Delos all begin to malfunction, causing havoc throughout the park.

Two years after the Westworld tragedy in the Delos amusement park, the corporate owners have reopened the park following over $1 billion in safety and other improvements. For publicity purposes, reporters Chuck Browning and Tracy Ballard are invited to review the park. Just prior to arriving at the park, however, Browning is given a clue by a dying man that something is amiss.