Ben and Kate re-enact the moment 50 lions were unveiled to the British public. Meanwhile, at the giraffe house, there is a tense wait as Ella prepares to give birth. Will the keepers need to step in and save her baby? And world-famous wildlife photographer Simon King attempts to take a snap of Longleat's Siberian tiger.

New recruit Jean Johansson discovers whether tigers like their eggs scrambled, fried or simply savaged. Meanwhile, the programme looks back at how the local vet 50 years ago adjusted from treating sheep and cows to lions and snakes. There also a heart-wrenching report on Anne, a mistreated circus elephant who could barely lift her trunk five years ago, but who has been looked after by three very special keepers.

The summer weather has caused the cheetahs to become lazy. To snap them out of their slumber, a contraption is being constructed that could ignite their hunting mode. But, able to hit speeds of up to 70 miles per hour, can the keepers make anything quick enough to truly test the cats?

The park opened in an attempt to save the enormous estate from financial ruin, but today it is the conservation of animal species that is the priority. World-renowned vets are racing to the park to try and kick-start the rhino breeding programme, and the stakes could not be higher. With the slaughter of white rhino continuing in the wild, what goes on in the Wiltshire countryside today could not be more important.

In the final episode, Ben Fogle gets mobbed by a flock of rainbow-coloured lorikeets as they undergo a vital healthcheck. Meanwhile, Kate Humble gets an extremely close-up view of the collection of giant stick insects by using a special camera. Elsewhere, the park is on lockdown as it prepares to move over 30 lions, the biggest collection in Europe, into a new enclosure. But the keepers have no idea how the big cats will react.