The story of Invasion America begins in the early 1980s, when humanoid aliens from the planet Tyrus begin to initiate their plans for making contact with Earth. Cale-Oosha, the ruler of Tyrus, looks into his uncle's project with Earth. However, his uncle, The Dragit, claims that their dying planet ought to invade Earth and take hold of its resources. Cale refuses, and a civil war breaks out.
Cale and Rafe, his bodyguard, trainer, and trusted friend, escape to Earth, disguising themselves as humans. Cale meets Rita Carter, a human woman; he falls in love with her, and they marry. After a long time of running from the Dragit's forces on Earth, Cale returns to Tyrus to help strengthen his loyalist forces, the Ooshati, leaving Rita and their young son, David, under Rafe's protection.
In the present day, when the Dragit finally finds the family, he is determined to kill them, and David Carter's teenage life is thrown into a devastating adventure of stopping the Dragit, losing and gaining friends, and finding out just who he is.