In Phoenix, the social assistant Beau Stark and the substitute teacher Cassy Winslow live together and are in love with each other and Beau proposes to marry her. Their best friend, the medical student Pitt Henderson is happy with the news. When Beau returns to his car, he sees a black stone that felt from the sky and when he touches it, he feels bad in a sort of influenza. When other black stones fall from the sky, there is an epidemic of influenza in Phoenix and Dr. Sheila Moran tries to convince his director to summon the CDC, but he says that it is not necessary. Soon Beau changes his behavior and Cassy tells Pitt. Their further investigation shows that RH- people have stranger reaction after touching the black stone that activates a latent virus in the humans that mutates them into an alien breed. Now Sheila, Cassy, Pitt and a few other humans are trying to find an antibody to save the human race. But no one can be trusted.
—Claudio Carvalho, Rio de Janeiro, Brazil