Tethered

"They look exactly like us. They think like us. They know where we are. We need to move and keep moving. They won't stop until they kill us... or we kill them."

- Red. "Gabe: Who are you people?, Adelaide: We're Americans."

- Adelaide about the Tethered.

The Tethered are the main antagonistic cult-like race of clones in Jordan Peele's 2019 psychological horror movie Us.

Biography
At some point in history, the United States government conducted an experiment that was held in America's many underground tunnels. The experiment, meant to control the public, involved the cloning of nearly every citizen in the United States. According to the real Adelaide, while the cloning of human beings proved to be successful, the experiment ultimately failed due to the scientists involved not being able to replicate the "soul" that real humans have. Due to this, the program was abandoned, and the Tethered were left in America's underground tunnels, where they were forced to constantly perform the actions of their real counterparts in various crude ways. They also had to survive off of consuming raw rabbits, who were the original test subjects of the experiment, as their main food source.

In 1986, Adelaide and her parents take a vacation to their beach house in Santa Cruz, and go to a carnival during the evening. While her mother uses the restroom, and her father is distracted while playing a game of Whack-a-Mole, Adelaide wanders off and discovers a funhouse with a hall of mirrors attraction. As Adelaide wandered off, her tethered, who mimicked her actions, inadvertently wound up escaping the underground tunnels, and also managed to discover the hall of mirrors attraction called "Vision Quest" (later renamed "Merlin's Forest" 3 decades later) in the process (as the funhouse served as one of the secret entrances to the tunnels in which the Tethered are kept). When the lights are knocked out due to a thunder storm, Adelaide gets lost in the hall of mirrors and sees her tethered, who strangles her unconscious, brings her down to the underground tunnels, and chains her to one of the beds. The Tethered version of Adelaide emerges to the above ground world, where she joins the real Adelaide's parents, and, unbeknownst to everyone else, assumes the real Adelaide's identity.

The Tethered version of Adelaide goes on to have a happy, stable life, while the real Adelaide is made to suffer for thirty odd years in the Tethered society. When the Tethered took note of her being different from them (due to her being the only person in the Tethered society that was human), Adelaide became their de facto leader, going on to formulate a revenge scheme in which she and the Tethered kill their above-ground counterparts (which she coined "The Untethering"), and form a gigantic line of themselves holding hands across the entire United States (referred to as "The Line") in a similar manner to the "Hand Across America" campaign that was held back in 1986, thus "making a statement". It is during this time that the real Adelaide dawned a new persona, now calling herself “Red”.

Shortly after the Tethered Adelaide and her family (consisting of her husband, daughter, and son) arrive to Santa Cruz for an annual vacation, Red sets the attack and nearly every denizen of the town is slaughtered by their counterparts. Red, assisted by her Tethered version of the Wilson family, invade the Wilson home, and orders her family to separate the Wilsons while she deals with her Tethered self; Gabe is dragged outside by Abraham, Zora is chased by Umbrae, Jason is forced to “play” with Pluto in a closet, and Red handcuffs Adelaide to a table in the living room. Eventually, the Wilsons manage to kill nearly all of their Tethered counterparts (With only Red and Pluto left), as well as the Tethered versions of their neighbors', and try to escape the town, only to see that the Tethered have formed a long line of themselves holding hands across all of California. After Jason tricks Pluto into walking into the flames of a burning car, Red kidnaps him, compelling her Tethered version to race after her. Killing her real counterpart, the Tethered Adelaide retrieves her son and escapes the town, making Jason the only family member who has some awareness of her true nature.