"So it begins," Felicity Jones says in the trailer for Amazon's "The Aeronauts," a hot air balloon adventure tale that sees her reuniting with "Theory of Everything" co-star Eddie Redmayne.

Set in 1962, the movie follows wealthy young widow Amelia Wren (Jones) and headstrong scientist James Glaisher (Redmayne) as they mount a balloon expedition to fly higher than anyone in history. It’s a journey to the edge of the then-known world, 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.

The story is based on the life of English aeronaut and astronomer James Glaisher. The film comes from director Tom Harper ("Wild Rose," "War & Peace" miniseries).

This marks the first reunion for Redmayne and Jones since "Theory of Everything," for which they were both nominated for Oscars.  Redmayne ended up winning Best Actor for his portrayal of Stephen Hawking. Maybe the duo will make magic again this awards season.

"The Aeronauts" will make its world premiere at the Toronto International Film Festival. It will open in theaters December 6, then begin streaming on Amazon on December 20.