While carrying on their usual hi-jinks, they inadvertantly stow-away on a spaceship bound for Mars. They meet up with the local Martian residents and cause them to invade the Earth, aided by the "Invincitron", a vacuum-wielding giant robot. Tom, Jerry and their Martian ally, Peep, save the day.

While carrying on their usual hi-jinks, they inadvertantly stow-away on a spaceship bound for Mars. They meet up with the local Martian residents and cause them to invade the Earth, aided by the "Invincitron", a vacuum-wielding giant robot. Tom, Jerry and their Martian ally, Peep, save the day.