界海
Four years later, Nigel is now based on the Moon. A fellow astronaut, Nikka, is involved in a crash that accidentally discovers a still active alien spacecraft wreck in the Moon's Mare Marginis – a spacecraft suspiciously armed with a once-powerful anti-spacecraft weapon. Nigel and Nikka explore the wreck, and find a functioning computer with a direct neural interface. Nigel and several others experiment with the computer's neural hook-up, and leave fundamentally changed by it, while the computer becomes inert and unable to reveal any more about its creators. Meanwhile, on Earth, some surprising experiments in human genetics conducted by the aliens are discovered alive in North America.