American short story that probably dates from the 1950s. An alien ship lands on Earth. The human race has been wiped out, possibly by the aliens themselves, although I'm not sure about this. It turns out that there are human survivors, something that puzzles the ship's doctor - everyone on Earth should be dead. Turns out they are dead - they're vampires. The vampires proceed to slaughter the crew. A few aliens take off into space, but the doctor knows they are doomed - all they are doing is taking the vampires back to their home planet. Knowing this, the doctor kills himself.