When the first manned flight to Venus returns to Earth, the rocket crash-lands in the Mediterranean near a small Italian fishing village. The locals manage to save one of the astronauts Colonel Calder, the mission commander. A young boy also recovers what turns out to be a specimen of an alien creature. Growing at a fantastic rate, it manages to escape and eventually threatens the city of Rome.

Emergency medicine intern Margaux can no longer stand it. During another very hectic and patient-filled shift, she forgets a homeless woman on a stretcher who then dies. Shocked Margaux has no choice but to continue working. But suddenly, her body starts sweating blood uncontrollably.