Prior to the events of the series, the original Speed Racer has disappeared for unknown reasons. Only one of the original characters, Spritle Racer, has a major role in this show. The rest of the original cast is unseen, and their whereabouts are unknown. Through the rest of the series, Speed and his new allies set out on a quest to get through the courses, discover the mystery of Speed Racer's disappearance, and try and build the Mach Six, a car that captures the spirit and gadgets of the Mach 5 for the new generation, and the first car to contain a gasless engine.