Troy Johnson works as a park ranger in the mountains of California. But besides his work in the nature park, which involves preserving the beauty of the mountains and keeping a watchful eye on visitors, Troy has another job: Together with his wife Jayne and their children Josh and Peter, the Johnsons train a wide variety of animals, some of them quite exotic, for Hollywood productions. They are supported not only by Greg Nickels, but also by their monkey Plato and their dog Muddy.