When a US space rocket crash-lands near a town in Arizona, the curious locals open the capsule to see what's inside. It's a bad move: almost immediately, the town's entire population, bar one old man and a baby, is killed by a blood-clotting, extraterrestrial pathogen.
A team of scientists from a government biotech lab, led by Arthur Hill, James Olson, Kate Reid and David Wayne, engage in the battle to defeat the alien life form before it wipes out mankind.
But, just as they seem to be making promising progress, the virus mutates into an even more virulent strain...
(1971) Cert: PG