With fewer than 100 individuals left on earth, the Sumatran rhino is teetering on the brink of extinction. But a newly signed agreement could provide light at the end of the tunnel. Producer Kirsten Horne and cameraman Mark Thorpe head into the humid rainforests of Indonesia's Way Kambas National Park to meet a team of hardworking conservationists tasked with saving the critically endangered species, and to find out firsthand whether the new declaration can bring this iconic animal back from the brink.