The retaking of First Warren was an action that the Resistance anticipated would eventually have to be taken in the war against the Lords of Prey. Following the first Citadel Congress, Harbone Citadel - the nearest of Secret Citadels to First Warren - was tasked with preparing for the eventual invasion. However, opinion greatly varied among the rabbits as to when the effort would take place, some feeling that it would be the final action of the coming war while others were convinced that it must be done early on. With this latter view in mind, Princess Emma dispatched Lord Captain Helmer and Captain Picket Longtreader to enter the city.
Picket and Helmer's infiltration succeeded, and they soon made contact with the few resistance forces established as the Citadel of Dreams. They then issued Emma's challenge to Winslow, nominal governor of the city, before making their way to the roof of the Governor's palace. Using a glider cape, Picket then flew up to the top of one of the city's Seven Standing Stones and, aided by other resistance fighters, set off a blastpowder explosion that toppled the statue of Morbin Blackhawk set atop it. The resistance forces then charged the city center, seeking to rescue the endangered younglings of the city.
Having been alerted to Picket and Helmer's infiltration and successfully marshaled the various secret citadels, Emma launched an invasion of the city shortly after the inner resistance forces began their attack. Blowing a massive hole in the outer wall, they flooded the city and engaged the wolf, rabbit, and Preylord forces housed within. During the battle, Picket and Coleden Blackstar, a fellow member of the Fowlers, joined in fighting the villainous Black Band. This conflict was ended when Helmer engaged the band's leader, Daggler, and killed him in single combat.
Part of Emma's strategy was getting forces up onto the outer wall of the city, though it was a costly effort, in order to prevent any Preylords from escaping and bringing word of the city's capture back to the High Bleaks. The raptor sentinels who had patrolled the city were eliminated, with Jo Shanks managing to shoot down the last one. Falcowit, a member of the Six who oversaw the occupation, then attempted to flee but was then killed by Emerson of Harbone Citadel firing off one of his Bowstrikers. Falcowit's death marked the end of the battle, with the other enemy combatants being swiftly defeated.
Having retaken First Warren, the Cause forces set about preparing it for a retaliatory assault by Morbin's forces. Emma, in an address to the populace, announced her intention to remain in the city and not flee to safety. She then issued a pardon to Winslow and those members of his regime who demonstrated contrition, assuring her people that all would be set right once the war was over.