For Frozen Planet II, the team wanted to film not one, but two of the rarest big cats on earth. Amur Leopards and Siberian tigers, with only 120 leopards and 500 tigers left in the wild, living in the freezing forests of the Russian Far East. This is the story of two incredible characters, whom without their passion, none of this would have been possible. Sergey has undertaken a project to capture imagery of these elusive cats. He has some help from expert Nikolai Agapov, a researcher who knows the forest well. Sergey and Nikolai offer unrivalled expertise of this incredible landscape. I’m heading to meet up with Sergey, who… his passion for leopards and tigers, spans decades. So, I’m hoping that we’ll be able to learn a thing or two from his knowledge and his expertise, to see if we can get leopards or tigers moving through this amazing landscape. Segey, with the help of Nikolai’s unrivalled knowledge has deployed a network of photo and video camera traps. Since its inception, the Land of the Leopard National Park has managed to triple the numbers of Amur leopards. So from here, Sergey, do the leopards start from over there? And then come this way, and then move on? You never know. Right. Tracks walking past a camera offer hope for an early success. But when it comes to wildlife, even the best laid plans don’t always reap the desired results. I want to cry, really. How close was she to the camera traps? Yes, it was on the road. Like five metres. But of course, our camera does not work at night. Disappointing. Likely it was very close. Yeah, very close, but not quite close enough. Camera traps are a clean way of gathering critical data in the park’s conservation efforts. But alternatives are available. Each piece of evidence is vital to this important piece of work. And each photo is shared with the park’s science department to create a huge database of images. Finally, the team get a glimmer of hope. Have you managed to see anything? Oh, right there. Amur leopard with snow. Oh that’s fantastic. My dream. She seems okay with the snow. Yes. Wow. Sergey this is awesome, you pleased? Yeah. That’s fantastic. I like it. My dream – snow, and an amur leopard. Fantastic. And once the success starts to come, it doesn’t stop. Over the seasons the team manage to film amazing imagery of these two predators surviving around each other. And more than that, thriving in these lands. For this incredibly rare leopard, every cub born marks a crucial landmark. Their hard work helps the Frozen Planet II team achieve intimate images, never seen before. And they get a privileged view of how big predators can exist together in one forest. As long as the amazing work of the park continues, the future of these cats is safe.