A doctor, an architect, an engineer, and a geologist step into a space car. In their new invention, they set off on an expediton to Mercury, planning to visit Venus on the return voyage. On Mercury they find a strange city eerily abandoned. Sculptures of giant figures alarm them. In a building they discover a machine. The engineer gets it running, and blaring out of the machine a thundering voice speaking Mercurian begins to sound in a way that conveys to them that it is telling a story. After an enormous effort the men translate the audio book...

In the Devolutionist, space travelers experiment with Venusian methods of telepathic space travel. They leave our solar system to discover and explore the earthlike planet Capellette of the star Capella. In the Emancipatrix, they go to the planet Sanus of the star Arcturus. In both unique worlds, they become embroiled in the struggles and challenges of the inhabitants, and much more. This is Book Two of the Dr. Kinney adventures.