Alan Alda admits being skeptical of zoos, but discovers parks working both to improve the lives of their captive inhabitants and to help restore wild populations. In San Diego, Alda visits polar bears and pandas that live in an environment designed with "enriching" simulations. He takes part in tuna tagging at the Monterey Bay Aquarium, then assists in the ER at the New England Aquarium when a puffer fish has a bladder stone removed.