After quickly establishing himself as one of the freshest voices in horror cinema with his Oscar-winning directorial debut Get Out, Jordan Peele returned with a sophomore effort that proved he wasn’t a one-trick pony. Like Get Out, Us is a social thriller with strong political themes; whereas Peele’s first film addressed issues of race, his second addressed issues of class and institutionalized inequality as a whole.

With a fiercely original script and a stellar cast including Lupita Nyong’o and Winston Duke, Peele created one of the best horror movies of the decade. Here are 10 behind-the-scenes facts about Us.

The Film Grew Out Of The Confusion Regarding The Genre Of Get Out

Despite the critical acclaim and commercial success of Get Out, Jordan Peele was disappointed that there was some confusion regarding its genre. The Golden Globes even nominated it in the “Musical or Comedy” category.

So with his next film, Peele set out to create a terrifying story that no one would mistake for anything other than an all-out horror movie. A big influence on Us was The Twilight Zone episode “Mirror Image,” in which a young woman is tormented by a doppelganger trying to take her place.

Jordan Peele Gave The Actors 11 Movies To Watch Before Filming

Before filming began on Us, Jordan Peele gave each member of the cast 11 movies to watch, so that they would all be on the same page about what tone they were going for.

This list included: The Birds, Funny Games, Jaws, The Shining, Dead Again, The Babadook, It Follows, A Tale of Two Sisters, Martyrs, The Sixth Sense, and Let the Right One In.

Lupita Nyong’o Based Red’s Voice On Robert F. Kennedy, Jr.

Lupita Nyong’o reportedly stayed in character as Red between takes. When she saw in the script that Red hadn’t spoken in years, she realized she had to develop something memorable with her voice.

She based it on a neurological disorder called spasmodic dysphonia, which causes involuntary spasms of the larynx. Robert F. Kennedy, Jr. suffers from this disorder, so she based the voice specifically on him.

The Remix Of “I Got 5 On It” Wasn’t Supposed To Be In The Movie

The trailer for Us featured a haunting remix of Luniz’s “I Got 5 on It” that went on to define the movie, but this song wasn’t originally in the movie. In the initial cut of Us, the climactic ballet sequence in which Adelaide attacks Red, and Red can see every move coming, featured Tchaikovsky’s “Pas de Deux” from The Nutcracker.

However, after the positive response to the “I Got 5 on It” remix in the trailer, Jordan Peele decided to add it into the film.

There’s A Hidden Nod To Get Out In The Hall Of Mirrors

Jordan Peele hid a little nod to his debut film, Get Out, in the opening scene of Us. As a young Adelaide wanders into the hall of mirrors on the Santa Cruz Beach Boardwalk, the words “get out” can be seen carved into the side of the front entrance.

The purpose of Get Out’s title was to warn the characters on the screen of the danger they’re in, so it’s interesting to see Peele continue that meta theme in his second film. Interestingly, there isn’t actually a hall of mirrors on the Santa Cruz Beach Boardwalk.

The Production Company Behind Get Out Couldn’t Afford Us’ Budget

After having a great working relationship with producer Jason Blum and his production company Blumhouse when he made Get Out, Jordan Peele wanted to reteam with them for his sophomore directorial effort, Us. However, Blumhouse only produces low-budget movies.

This was fine when Peele made Get Out and only needed a budget of $4.5 million, but Us came with a $20 million price-tag. Blumhouse couldn’t raise the $20 million, but Peele still wanted to work with Blum, so Universal footed the bill and hired Blum as a producer on a one-off basis.

The Twins Got Their Start When They Played Emma On Friends

The twins that appear in Us, Cali and Noelle Sheldon, may not be immediately familiar, but any fan of Friends has seen their previous work.

Their first role was playing Ross and Rachel’s baby daughter Emma in the last couple of seasons of the show. (Hollywood producers cast twins to play babies in order to get around child labor laws.)

The Rides On The Santa Cruz Beach Boardwalk Were Filled With Dummies

The production crew didn’t have to make a lot of alterations to the Santa Cruz Beach Boardwalk to dress it up for the ‘80s setting, since the boardwalk has had most of the same rides since the 1910s. During filming, all the rides were filled with dummies, which were later given digital movements in post-production.

There is actually a network of underground tunnels beneath the Boardwalk, although it’s used for storage and emergency shelter, not a home for the clones created in a failed U.S. government experiment.

Us Is Filled With References To The Shining

Stanley Kubrick’s The Shining is one of Jordan Peele’s favorite horror movies, and it shows in some of the imagery used in Us. The overhead shot of the Wilsons driving to their vacation house is taken from the opening of The Shining, while the twins and their simultaneous speech were influenced by the Grady twins.

Duke Nicholson’s characters are named Danny and Tony, a reference to Jack Torrance’s son and his imaginary friend in The Shining, and Jordan Peele told him to play the roles like Lloyd the bartender, without realizing he was Jack Nicholson’s grandson.

Jordan Peele Used Hands Across America As A Plot Device For A Specific Reason

The “Hands Across America” charity event from 1986 was chosen as a major plot point in Us for a very specific reason. This event was pretty much a disaster, bringing in almost no money due to massive overheads and widespread unpaid pledges. Jordan Peele uses this failure to critique charity and, more broadly, the hypocrisy of society’s lazy attempts to fix institutionalized inequality.

The Tethered’s own human chain at the end of the movie comes with an ironic play on Michael Jackson’s “We Are the World,” which was the anthem of Hands Across America.