Not as engaging or humorous as previous Cain novels by Mitchell, this one finds the reluctant hero retired on his "home" world of Perlia spending his time as an instructor at a local schola. His reputation from a previous battle on Perlia precedes him as the local PDF and other known officers of previous skirmishes seek his counsel and Hero status as a plot is uncovered of Chaos forces planning a raid on the planet in search of an artifact of immeasurable power. This object, the Shadowlight, was used in a previous Cain book, and Cain figures it must be protected at all costs. What he ultimately discovers is a Xenos plot that could lead to even greater disaster in future Cain books. Mitchell spends an inordinate amount of time on set up and bureaucracy in this one, and the reader needs a certain amount of discipline to get to the better parts near the end.