This action-packed series follows Nigel Marven to the Pantanal in Brazil, the world’s biggest wetland and home to the planet’s largest population of jaguars – the least known of the big cats. In the final episode of the series, Nigel completes his adventure with a risky journey into the heart of the jungle for a face-to-face encounter with the king of the Pantanal.

Over the past four weeks, Nigel has enjoyed the vast array of wildlife on offer in the Pantanal. He has wrestled with caiman and anacondas, swum with capybara and giant otters, and realised his childhood dream of meeting jaguars in the wild. All of his jaguar encounters so far, however, have been from the relative safety of a boat. Now, he has set himself one final challenge – to get up close to a wild jaguar on foot, and learn the future of this wonderful animal. “Getting up close to a jaguar would be a really fitting finale to the month I’ve spent in the Pantanal,” says Nigel.

With two days left of his trip, Nigel has travelled to the Caiman Ecological Refuge in the south of the wetland. Here, open-minded ranchers hope to make peace with the jaguars, despite the fact that the hungry predators kill their cattle. Determined to protect the big cats from deadly retaliation at the hands of less-liberal ranchers, biologist Leandro Silveira tracks and tags the animals to learn about their behaviour. Early one morning, Nigel joins Leandro and a crack team of scientists, cowboys and hunting dogs for a dash through the wilds of Brazil in pursuit of a jaguar to tag. “This may look like something out of ‘The A-Team’,” explains Nigel, “but it’s the only way of coming face to face with the Pantanal’s greatest predator.”

Nigel and the team return to a dead cow they discovered yesterday in the hope that a jaguar has returned to the kill overnight. The hounds quickly pick up the cat’s scent and lead the trackers into the forest. “This could be it,” says an excited Nigel. As they move rapidly through the trees, a radio message from another team brings news that a cowboy has seen a jaguar nearby. However, after a frantic scramble, the dogs lose the animal’s scent, suggesting it has left the forest floor and climbed high into a tree. “So close, yet so far,” says Nigel. “The jaguar has eluded our army once more.” As dusk approaches, the day’s hunt comes to an end without success, leaving Nigel tired and frustrated.

The search for jaguars cannot begin again until the following morning, so Nigel decides to spend the evening searching for other animals on the ranch. Before long, he encounters an armadillo foraging for grubs and insects. Armadillos have a keen sense of smell but rather poor eyesight, meaning that Nigel can get very close to this specimen. “This one’s struggling to spot me from just a few metres away!” he exclaims. Later that night, Nigel witnesses a group of peccaries eating corn left out by a farmer. These hog-like animals look friendly, but they have razor-sharp canines and can attack in packs, making them one of the most dangerous animals in the Pantanal. “I really don’t want them to notice me,” whispers Nigel.

As the sun rises on the morning of Nigel’s final day, the scientists decide to bring out their secret weapon – a radio-tracking device that will enable them to follow a jaguar already fitted with a collar. “This is it –my last chance to come face to face with a jaguar in its jungle home,” says Nigel as the hunt begins.

A radio signal reveals that a female jaguar is holed up in a small clump of forest nearby, so the hounds and the trackers get into position. Every move is critical, since a cornered jaguar is an extremely dangerous proposition. Suddenly, everyone in front of Nigel rushes to the same spot and looks up into the trees. When Nigel catches up, he follows Leandro’s gaze and sees a large female relaxing in the branches above. “It reallygets you there, being so close to such a magnificent animal,” says Nigel pointing to his chest. After four weeks in the Pantanal, this is the closest Nigel has ever come to a jaguar, but there is one final surprise in store that promises to end his adventure on a huge high.