In "The Satanic Illusion," L. Sprague de Camp focuses on the conflict between believers in creationism and believers in evolution. Reginald Rivers, his partner Chandra Aiyar, and many other hunters using a time machine to travel to prehistoric eras have been bringing to the present a great deal of evidence supporting evolution as the explanation why animals and plants have achieved their present forms. This has disturbed supporters of creationism, some of whom have picketed the offices of Rivers and Aiyar: "The signs they carried denounced the Raja— that is, my partner Chandra Aiyar—and me as murderers and emissaries of Satan.

I was never quite clear as to whether one of us was supposed to be Old Nick himself, and the other an assistant imp."

Rivers made the mistake of saying in a speech to the West Side YMCA that he, as the...