Ben Fogle and Kate Humble explore life behind the scenes at Longleat Estate and Safari Park. White rhino bull Winston becomes a sperm donor; will artificial insemination allow him to become a father at last? The Pere David deer are hovering on the edge of extinction, but can Longleat help save the species? The bat cave needs a makeover, but first Darren and his troops must round up the bats. And there is also a stakeout to see the lions tucking into a special midnight feast.