10 Clever Ways Horror Movies Foreshadow the Ending

In Jordan Peele's second feature Us, Adelaide and her family are on holiday when they're attacked by their doppelgängers, who call themselves the Tethered.

During the film's climax, Adelaide's double, Red, explains how the US government created clones of its citizens decades ago, hoping to control society. When the experiment failed, the duplicates were abandoned underground.

It's a lot of exposition to take in, but it feels necessary since the audience needs to understand what the Tethered are and where they came from. However, everything about the Tethered was hinted at in the first five minutes of Us, with the opening scene showing a television playing a commercial for the Hands Across America charity event. 

Viewers should be focused on the TV, so they probably won't notice the video tapes on the left, including one in particular called C.H.U.D. In this 1984 B-movie, a group of New Yorkers discover the sewers are populated by savage monsters. Over time, the ensemble learns that these creatures are humans who've been mutated by toxic waste that was dumped underground by corrupt government officials.

C.H.U.D. and Us appear different on the surface, but both centre around subterranean humanoids who've had their lives destroyed by the callous government, encouraging them to attack the surface world. Although it's not stated directly what the Tethered are until the 90-minute mark, eagle-eyed viewers could've figured it out within the first few seconds.