The sky's the limit for Felicity Jones and Eddie Redmayne.

"The Theory of Everything" stars are reuniting for "The Aeronauts," which just started filming in the U.K.

Amazon Studios released the first photo, along with details on the film and the stunt work the actors are doing themselves.

Here's the film synopsis:

"Set in 1862, 'The Aeronauts' follow wealthy young widow Amelia Wren (Felicity Jones) and ambitious scientist James Glaisher (Eddie Redmayne) as they mount a balloon expedition to fly higher than anyone in history. This is a journey to the very edge of existence, where the air is thin and the chances of survival are slim. As their perilous ascent reveals their true selves, this unlikely pair discover things about each other – and themselves – that help them find their place in the world they have left behind."

Check out the beautiful first photo:

Producer Todd Lieberman shared details on the photo, and plans for more balloon work:

"A top priority for us on 'The Aeronauts' is authenticity. With that in mind, we intend to do as much balloon filming in the sky as the weather will allow. This image was taken after we launched Felicity and Eddie 2,000 feet in the air, performing their scripted scene, while a helicopter captured it all. We’re fortunate that Felicity and Eddie have the nerve to do these stunts themselves as it authenticates our entire approach."

Good for them. Looks fun, too, if you aren't afraid of heights.

Tom Harper is directing the film, which also stars Tom Courtenay, Anne Reid, Rebecca Front, Tim McInnery, Phoebe Fox, and Himesh Patel.

No release date has been revealed at this point. Cross your fingers that Mother Nature provides perfect balloon filming weather throughout the production.

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