An Earth archaeologist is caught by a "zeta-beam" and teleported to Rann near Alpha Centauri where he meets Alanna and Sardath. Alien invaders, called The Eternals, attack the planet while Adam and Alanna journey to the Brigadoon-like city of Samakand to locate a life-metal called "vitatron." Adam tricks the aliens so they're stuck in Samakand, but then he fades away, returning to Earth, awaiting the next zeta-beam.; Zapped by the zeta-beam, Adam is teleported, not to Rann, but to Anthorann, a neighboring planet. Escaping barbarians and their "Rainbow Doom" (a teleporter), he meets Alanna and Sardath, who had used knowledge from Samakand scientists to journey to Anthorann, but crashed. Adam dons a Rann spacesuit from the wreckage and faces invaders from Morleen, who swing a "diamondium" pendulum to cut open the dome of New Ranagar. Adam ray-blasts the shaft, then fades away to Earth.; Educational facts about space, the sun, and stars.; Educational info on Tebutt's Comet, Halley's Comet, and the Pons-Winnecke Comet.