The colony is still recovering from its war with the Vemus, but now they face a new threat. Something is causing a major upheaval among the creatures of New Earth, and the Colonial Defense Force is in trouble.

A new discovery sheds light on what happened to the alien race that inhabited New Earth, and their fate may affect whether the colony survives. As the scientists race to unravel the mystery, hordes of super-predators are rushing toward colonial settlements, and Connor must find a way to stop them before all is lost!

Sanctuary is the fourth book in the First Colony military space opera series.