A time-patrol officer named Roger and a ruthless criminal named Gustaf both slip through time from 2993 AD, their ships locked in combat, and crash-land on a prehistoric planet sixty-five million years in the past. Roger crosses paths with Wolf—another pursuer of Gustaf—and the two join forces. Gustaf has turned a living dinosaur into a weaponized combat creature, giving him a deadly edge in the jungle. Roger and Wolf track him together, combining their skills against an enemy who has begun adapting the ancient world to his advantage.