Exclusive: Following the success of The Family Plan last month, Apple Original Films and Skydance are reteaming on another tentpole as Deadline is hearing John Krasinski and Natalie Portman are set to star in Fountain of Youth with Guy Ritchie directing. Skydance Media will serve as the studio, and the film will be produced for Apple by Skydance, Vinson Films and Project X Entertainment.

Written by James Vanderbilt, the pic follows two estranged siblings (Krasinski and Portman) who partner on a global heist to find the mythological Fountain of Youth. They must use their knowledge of history to follow clues on an epic adventure that will change their lives — and possibly lead to immortality.

Hailing from a first-look partnership between Apple and Skydance Media, Fountain of Youth will be produced by Skydance’s David Ellison, Dana Goldberg and Don Granger. Tripp Vinson will produce through his Vinson Films as will Project X Entertainment,...