 Astronaut John Blackstar s shuttle passes through a black hole and crashes on the planet Sagar. He is rescued by the gentle Trobbits, who live under the tyranny of the Overlord, possessor of one half of an all-powerful sword. Armed with the other half, Blackstar aids the resistance with his dragon, Warlock; the shape-shifter Klone; and the sorceress, Mara.