Inside the grounded starship, its Skyborn inhabitants feed on their hatred of the dreaded and despised Earthborn. When, on routine patrol, a Colony scout is captured by the Family, he reveals a startling secret: Authorities onboard Colony have regrouped and mean to launch a final─and overwhelming─ assault to rid Earth of the ‘savage’ Earthborn once and for all.

Welkin has only one choice: Infiltrate Colony and neutralise the threat. But even Welkin─armed with his knowledge of Skyborn ways and methods─could never have been prepared for what he finds.