Looking after a defecting scientist should have been Ferec's easiest mission. But now he's on the run from the intelligence agency he works for, dodging a handler who might have gone rogue and relying on a secret patchwork of illicit resources and dodgy contacts. Turns out his defector might be carrying an apocalypse-level magical weapon - and protecting it requires Ferec and his team to go underground, literally. Down here, the rules are very different... and the tense peace between every city in the world will shatter unless Ferec can drag their darkest secrets into the light.