The two perform "Rewrite the Stars" in their new movie musical "The Greatest Showman."
The ballad, "Rewrite the Stars," is all about star-crossed lovers, with Efron's businessman character Philip Carlyle trying to convince Zendaya's Anne Wheeler - a trapeze artist - that they are supposed to be together.
According to an interview with the song's writers, Benj Pasek and Justin Paul ("La La Land"), the tune wasn't an easy one. They told the L.A. Times that they knew the scene would involve a trapeze and began to think of it as "two people longing to soar together."
"To know the staging — they're literally flying through the air — really frees you up to write music that matches that idea," Pasek explained.
Hugh Jackman also stars as P.T. Barnum in the film, which, according to the official synopsis, "celebrates the birth of show business & tells of a visionary who rose from nothing to create a spectacle that became a worldwide sensation."
'The Greatest Showman' hits theaters December 20, 2017. Watch a few more videos from the set and check out a couple other songs from the soundtrack below.