Ben and Dr Grant Hopcraft follow the wildebeest herd as they tackle the dangerous currents and fearsome predators that lie in wait for them at the Mara river crossing.

As the rains arrive, the million strong wildebeest herd divides in two and heads west, while Ben meets rangers on a private reserve who are pioneering a strict anti-poaching regime.

Ben joins Dr Grant Hopcraft, one of the world's leading researchers of wildebeest, to tag four wildebeest to monitor their individual progress on the migration via a GPS. He also takes a hot-air balloon ride, camps out among the wildebeest and lions, and meets members of the Maasai and Hadzabe tribes.