On Earth in the not-too-distant future, Will Perkins looks at Luna almost every evening.He dreams of visiting there, living there, someday.

Finally, almost through a fluke, he realizes his dream. He and his wife Rose will live in the well-established Arzachel 1 crater colony while he works as part of a crew to build Arzachel 2.

But nothing ever goes quite as planned, does it?

Even as Will and Rose's lives are changing, so is the face of reality as they know it.

What causes the earthquake-like vibrations that tremor regularly through Arzachel 1?

There are rumors of an alien force staging a planned invasion of Earth. But human nature tends to ignore feelings of dread rather than face them head on.