The Ministry of Our Hidden Mistress leads a revolution against the cruel aelfir rulers of Spire - and to get their really dirty work done, they recruit dangerous people who made their name on the frontier between reality and unreality in the Heart. Vermissian Black Ops is a sourcebook for Heart: the City Beneath that gives additional rules and guidance on using the corebook to tell stories of blacktops actions against high value targets in the City Above. Additional advances allow players to customize their characters, new fallout results help the gamesmaster simulate tense squad-on-squad action, and an alternative advancement system lets characters grow and prosper by taking on difficult missions. The sourcebook also breaks down the infamous Vermissian Network - a cursed mass transit system - line by line, detailing the factions that have made it their home, the natural and unnatural threats that await explorers, and plenty of plot hooks to spice up your games.