Earth is dying. Its resources are contaminated. Plagues have decimated the population to a mere two million - a population number not seen on Earth for 50,000 years. With time running out, Earth sends probes to find suitable planets to move its population to before their impending extinction. Project Arcturus is born. An advance party is sent to the distant world of Arcturus to eliminate the current population. The force does not expect the post-Iron-Age civilization to be any threat at all.