In the penultimate book of Michael Pryor's brilliant steampunk adventure series, the war that has loomed for so long is finally declared. Can Aubrey's magic save him this time?

The unthinkable has happened: Albion is at war. Aubrey and George are swept up into the military - but not in the way they expect. With Caroline drafted into the Special Services, Aubrey is sure the combination of his magic, George's practical skills and Caroline's fighting secrets will make them a formidable team. But what if the military hierarchy has other ideas?
When Aubrey's top secret espionage unit is sent to Gallia to investigate mysterious magical emanations, what they discover is intelligence gold. Holmland is about to unleash an unstoppable horror upon the world. It could win the war within weeks. Aubrey is in a dilemma: should he obey orders and simply observe, or should he and his friends do their best to stop a bloodbath?
Saving thousands of lives could cost Aubrey his own. But that's never stopped him before.