In the parallel world first introduced in S. M. Stirling's The Sky People , aliens terraformed Mars (and Venus) two hundred million years ago, seeding them with life-forms from Earth. Humans didn't suspect this until the twentieth century, but when the first probes landed on...
In the parallel world first introduced in S. M. Stirling's The Sky People , aliens terraformed Mars (and Venus) two hundred million years ago, seeding them with life-forms from Earth. Humans didn't suspect this until the twentieth century, but when the first probes landed on...