Even though we know the main plot and saw the trailer for Us, we still know little about it. Peele created the monsters/doppelgangers, The Tethered, and it's probably going to remain ripe for theories until its release.
Jordan had Lupita watch 10 movies, from The SHining to Martyrs, to create a "shared language" with the actress.
Some of the others were...
A Tale of Two Sisters
The movie, set in present day, stars Winston Duke, Lupita Nyong'o, Shahadi Wright Joseph, and Evan Alex. Us hits theaters March 15, 2019 and the trailer debuted on Christmas day