The powerful dog Rex is injured by a car while rescuing a young scientist from being run over. Feeling responsible for the condition of Rex the scientist uses his skill as a prosthetics inventor to give the dog a new, super-power body. With this Rex suddenly finds himself chased by two thugs who want to steal and sell the technology of his super prosthetics. When they even do not stop at kidnapping his teenage owner, Rex has to take the challenge of the rescue of his friend.