Walter Ernsting (known among English-speaking science fiction fans as Clark Darlton) conceived of "The Day the Gods Died" as a dramatization of the ideas introduced by Erich von Daeniken ("Chariots of the Gods"). Ernsting, co-creator of the "Perry Rhodan" series, is a close friend of von Daeniken's. In fact, the latter has credited Ernsting with providing a spark to many of his theories.

Ernsting wrote "The Day the Gods Died" in the highly readable style familiar to Perry Rhodan fans. An added element of interest comes from the fact that part of the book, such as the description of wartime occupation service in Norway, is autobiographical. Using a device reminiscent of "Erehwon" or "The Wizard of Oz," Ernsting has his central character drift out of the known world and into a speculative fantasy. In the end, von Daeniken's ancient astronaut theories find direct confirmation.

Ernsting wrote this work with the full intention of helping to develop popular acceptance of von Daeniken's ideas. This may have made the book rather too polemical to stand on its own as a work of fiction. However, ancient astronaut enthusiasts and science fiction fans (perhaps one and the same) will enjoy this almost forgotten work.