Atlantic Productions’ documentary for PBS Nature, kicking off the strand’s 41st season. The film follows two Maasai guides, Derrick Nabaala and Evalyn Sintoya, who have spent a decade tracking the Great Migration as more than a million wildebeest, alongside zebra, gazelle and elands, journey through Kenya’s Mara ecosystem. A spectacle visible from space, the migration is now threatened by climate change, poaching and growing tourism. Written and directed by Joanne Scofield, produced by Anthony Geffen, with cinematography by Bob Poole.