A roboticist, Miss Lillian Howe, arrives at a new paleontology encampment and is shown around by Dr. Clarance Fullerton. Robots outnumber humans here. She is here to sabotage the site. Dr. Mandeville, Lillian's former teacher, sends her because Fullerton dynamites his finished excavations so that Mandeville won't discover anything left behind. The two are bitter rivals. Lillian is fascinated by another fossil hunter, Mrs. Hattie Bond Cunningham and her late husband. When it becomes known that Howe can perform seances, she brings him back to speak. It does not go as planned. Instead of a man's spirit, what Howe sees looks like a bird, and it is yelling about "our bones." It is maybe for the best that he didn't show up, because Hattie admits that the two were never really in love, she had more of an affinity to women anyway—perhaps to Lillian. Later Lillian tries to do automatic writing to communicate with her mother, but again she keeps hearing about bones. About eating the bones. She sees herself doing it, feeling her teeth scrape bone. Eventually she finishes disposing of the dynamite. When she does, she finds herself closing her mouth around a dinosaur bone, and suddenly she understands what it is all about. Hattie sees and is horrified. Lillian's disposal of the dynamite is not virtuous like she thought. She has been too trusting. Mandeville attacks the encampment, which Lillian has now left without protection. She has to man another robot to fight the attacking robot off, but she totals it. Just when she thinks she's failed, the bird creatures appear. They swarm the robot. Since she has proven herself, they have come to help. But they aren't birds at all; they are dinosaurs. Lillian ends up explaining herself to Hattie, and they end up together.