Biohazard! In a post-9/11 world, the very word strikes fear in the heart of people around the globe! And now, a deadly chemical agent has been released over Mount Rushmore, rapidly spreading through the surrounding countryside! Is this a terrorist attack on American soil? That's what the Avengers seek to uncover as they brave the lethal perimeter of the Red Zone - but the truth they uncover is more startling and terrifying than even that!