The planet Krishna, a satellite of the star Tau Ceti, harbors civilized natives who look much like Earthmen, save for minor anatomical differences like greenish complexions, blue-green hair, and antennalike organs of smell. Their culture is roughly medieval, and Terrans are forbidden to impart advanced technology to them.
To Krishna come two rival paleontologists to dig for fossils. As guide and interpreter, one has hired the veteran tour guide Fergus Reith; the other, the beautiful, brilliant, but headstrong and domineering social scientist Alicia Dyckman.
The situation becomes explosive because of the hatred between the scientists, and native priesthood's fear of their evolutionary ideas, and the fact that Alicia is Fergus's former wife. From these tensions grow a tale of wild adventure, scientific conflict, fanaticism, kidnapping, piracy, swordplay, and hilarious mishaps.