Traitor of Planet Venturion
Zeta was captured by outer space creatures similar to human being when he had an expedition alone with his spacecraft to Saturn's rings. 
The creatures made a colony in Titan, the biggest satellite of Saturn. 
The chief of Titan's colony, named Domars, were ambitious to make a series of experiments to Earth human being. He ignored the fact that some of the medical experiments could cause death to Zeta. 
That's why two of his staffs, Thena and Art, were secretly against him. Having no other solution, Thena let Zeta go.
Zeta didn't know how was Thena's fate, until one day she came unexpectedly to Phobos Station. [Phobos is a satellite of Mars].
[Flashback]
Domars was very angry with Thena, so he sue her to their leader, Olympiad Ax, for being a traitor. Thena was taking Art's fault too, since she thought that she could fly but Art couldn't. She was sent to Planet Okranion, a hot exile planet for scientists who did crime. Her friends, Art, Kron and Esta, could do nothing to help her. In Okranion, she must do some good resulted researches, if she didn't intend to be moved to do rough works in Planet Deronium, a hotter exile planet with mines and metal factories. After solving the hot condition in every buildings there with the special stuff her spacecraft was made and using the solar energy for the cooling system similar to her spacecraft's, she escaped and flew to Sun Solar System.
But Volcanos, Olympiad Ax's nephew who secretly planned a coup d'etat, instructed Domars to lead a team to chase her. Domars, being ambitious to kill Thena, led the team to fly to Sun Solar System. Just after he threatened to attack Phobos Station, Thena escaped again and was chased.
Meanwhile Art, Kron and Esta solved the mystery behind by decripting a difficult password Thena put on a disk, that contained a secret conversation between Volcanos and Domars about the coup d'etat. They reported it to Olympiad Ax, so the coup d'etat was failed.
Kron was sent to save Thena. He asked Zeta who was in Phobos Station to help him. 
Thena was in critical condition. Her spacecraft was hit and began out of control. She almost fell to Black Hole. Kron saved her by shooting a very tough net. But Domars was attacking again. This time some functions in Thena's spacecraft were damaged and her left arm was trapped in the middle of the mess, so she couldn't move. Before she become unconscious, she tried to turn on the automatic control switch. Kron had no choice than shoot his powerful weapon to destroy Domars. Domars' spacecraft exploded, but whether he could escape, nobody knew.
They flew toward Planet Venturion. Kron must land his spacecraft and Thena's in a very dangerous position.  Thena did what she still could do with landing function though her spacecraft was pointing backward and on the same moment Kron released the net. They landed safely.
Olympiad Ax rehabilitated Thena's name. 
Later, Thena and her friends brought Zeta back to Phobos. 
They were good friends now. 

First version of cover.

Second version of cover, added later as jacket cover.

[published by P.T. Pustaka Utama Grafiti, Jakarta, Indonesia, in 1987] 
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