The evil Lars Mangros plans to broadcast a subliminal signal during the next performance of the rock group Andromeda that will cause the youth of the galaxy to riot. Buck infiltrates Musicworld, where the broadcast will originate, in an attempt to stop the madman from destroying the galaxy's cities.

Buck journeys through a space warp into another universe, where he discovers that the peaceful planet Pendar is being threatened by the sinister war witch Zarina. The Pendarans enlist the aid of Buck and Princess Ardala, who had followed Buck through the space warp, and an unsteady alliance between the humans and Draconians is formed as Buck leads a combined fleet against Zarina's battlecruiser.