"Nobody knows where Xenos came from," said Drake. "But we know that first and second contact was on Earth back in the twenty-first century. We didn't encounter them again until 2122. These things are not natural." He sat on his cot. "As far as I can tell, it's like God, or Satan, or whatever decided to make the perfect predator and bioweapon. And I'm sure people want to get their hands on them for the latter purpose."