Kilroy, a glib aquarium-trained orca (killer whale to you), pals around with a talking seagull named Morris and longs, above all, to know what makes human beings tick. Frustrated by his boring tricks, despairing of communication, and appalled by human insensitivity (""You mean they have to have a society to keep people from being cruel?""), Kilroy grows lethargic and is returned to the sea where Morris helps him find food until he can rejoin his old pod. The accurate descriptions of orca behavior, particularly the pod's attack on two unsuspecting sperm whales, can work against the depiction of Kilroy as a cracker-barrel philosopher with a distracting resemblance to Charlie Tuna. For some readers, Kilroy's insight--that species can do what comes naturally and still respect each other--will transcend the problem of his split personality, and there is one magically moving moment when Kilroy's pod and a group of scientists meet at the shoreline to shout greetings to each other and ""for a few minutes there occurred a wild ballet in the light of the moon in which both men and animals were alike."" Whatever his limitations, Kilroy's ability to preach ecology without losing his sense of humor earns him a hearing.