Junkworld - a planet for discarded machines. Fresh off his latest victory, it is here that champion fighting robot Leroy Brown inexplicably finds himself. Certain his presence on Junkworld is a mistake, Leroy makes it his mission to go home.

Enter the Top Dog. A tyrant determined to conquer all of Junkworld, the Top Dog demands Leroy's capture for reasons known only to himself. This mysterious focus on Leroy ensures it is only a matter of time before Leroy's mission to return home intertwines with the fight against the Top Dog.

But just when Leroy Brown shows he may be the best hope Junkworld has, his entire world threatens to collapse - with devastating consequences.