the alien compulsion. The Jovian Sun-tap station sits on Callisto. Burl shuts it down and he and his two companions leave immediately, barely escaping the explosion of the booby-trapped station destroying itself. Partway to Saturn they encounter a Plutonian ship, a dumbbell shaped, globe-and-rod craft that launches what looks like a lightning bolt at Magellan. The bolt is absorbed by the bazooka rocket that the men had already launched at the alien ship. A tactical atomic bomb on a rocket obliterates half of the Plutonian ship, which flees. At Saturn they find the Sun-tap station on Iapetus and, wary of booby traps, drop an H-bomb on it. At Uranus the Sun-tap station sits on Oberon and again they wipe it out with a bomb. Then they head toward Pluto, figuring that they will hit the Sun-tap station at Neptune on their way home. They soon overtake the half-ruined Plutonian ship, which hits Magellan with an energy bolt that nearly cripples the ship, but then Burl obliterates the alien completely with an atomic blast. Arriving at Pluto, an Earth-sized world, the Earthmen discover the last Plutonian city at the north pole with two dumbbell ships hovering over it. They put Magellan into a low equatorial orbit to avoid being spotted while they finish repairing the ship. Burl and two companions go down to the surface to explore, working their way north and landing their small rocketship several times to examine a dead Plutonian city. Finally they come to within a mile of the planet's last stronghold. They infiltrate the place, set out a small atomic bomb with its timer set for four hours, and try to leave. Discovered and chased by Plutonians, Burl is trapped and knocked out. He regains consciousness in a transparent enclosure on the surface of Triton, just outside the main temple of the Plutonians’ lunar religion. He finds the controls and frees himself, then he joins a ragtag band of Neptunians while Magellan lures the two dumbbell ships out into space where the crew destroys them both. Inside the temple Burl finds the inner sanctum lined with glass cases containing aliens, including one of his companions, in suspended animation, waiting to be sacrificed. Burl battles the priests and smashes the cases in a desperate fight. As each alien regains consciousness it joins the fight and soon there are no more Plutonians. With all of the Plutonians dead,