Long ago, towards the end of humanity's first expansion into space, the vast majority of worlds were terraformed under the auspices of irascible genius Avrana Kern. But Kern had rivals, and a team of self-proclaimed innovators took one world from her remit and devoted themselves to reshaping it into a paradise in their own image, using new and unpredictable methods.
Later, after the fall of their society and long generations in the wilderness, the new and desperate return of humanity into space is focused on ark ships heading to all the worlds they believe - or hope - their ancestors made into welcoming homes for human life. Whilst most head for the planets that Kern's people worked on, ancient records show another pristine world, and an invitation from the ancients to inhabit it.
Later still, a ship with a crew of maverick humans, spiders and a spectacularly punchy mantis shrimp captain named Cato rediscover the world, and the ark. On their ship, the human Alis wakes up from a nightmare of conflicted realities to discover that she, Cato and the ship's version of Kern are the only ones left on board. Everyone else went to explore the ark and the planet, and now all contact has been lost.
Traumatised Alis and Belligerant Cato must follow in the footsteps of their crewmates to discover the full magnitude of what was done to this world by its terraformers, and to rescue the one surviving member of their crew from the surface - before she becomes a greater threat than anything the world itself can produce.
