7 years on from the original Fortress movie, Brennick and his family are still on the run. Finally, they give in, and surrender, only to find themselves imprisoned in a new, more sophisticated fortress prison in outer space. But Brennick's not a man to give in easily, and with a 10 year old son waiting for him back on earth, he's going to pack some serious assault on the evil corporation.

An android fighting-machine is charged with destroying a small brigade of rebels in a Latin American war who are fighting to maintain their freedom and protect their village. Contrary to his programming, Peebles decides to stay and assist the rebels in their plight. Having gained this information, his "creators" develop a more powerful android to try and defeat him.