After being attacked by an unseen force, Major Jeff Walker, a Martian colonist is trapped in another universe via wormhole, and lands on an earth-like planet. Befriended by amphibian-like beings, they live in peace until an outside force threatens their way of life. They must join an intergalactic war against an evil race called the Tolarions, and a warmonger who calls himself Balta. On a nearby planet, they meet a telepathic arthropod named Zarcon, who is a representative of the opposing peaceful Galactic Republic of Peaceful Civilizations. When his superior, Riona, double crosses the Republic and steals a weapon of mass destruction for unknown purposes, Walker and a band of misfits must stop him before he exterminates every race in the galaxy. Meanwhile, the Tolarions have plans of domination and conquest. Walker is unaware, however, that the key to their survival lies deeply rooted in the human's own historical past, and a man his grandfather once knew.