Rin Tin Tin is one of the most famous dogs in the world. He has his own TV show, he's the star of several movies, and there are cheering crowds wherever he goes. But when the big German Shepherd travels to the jungles of Central America to star in a movie about the legendary Lost King of the ancient Mayans, everything goes terribly wrong. He and his co-star, a dainty little Himalayan cat named Zizi, become lost in the rainforest. And then, to make matters even worse, they find themselves confronted by a pair of jaguars! Is this Rin Tin Tin's last adventure?