When the Verghast metropolis of Vervunhive falls under assault by the armies of Chaos, several Imperial Guard units, including Gaunt's Ghosts, are deployed to fend off the ravening hordes of fallen Ferrozoica. Peaceful Vervunhive, a munitions manufacturer for the broader Imperium, is rocked by a sudden assault from its neighboring hive-city, Ferrozoica. The initial defense falls into disarray due to disagreements among the Vervunhive military and governmental elite. In the initial engagement, Vervunhive loses its outlying factories and hab blocks completely, creating a humanitarian crisis within the city's walls. During the struggle, Imperial commissar Kowle becomes known as a hero when he returns from a failed tank assault with information on the enemy's size and disposition, despite the brutality of his actions during the struggle. Vervunhive signals its fellow cities as well as the Imperium for assistance, and forces arrive to aid the defense, including the Tanith First and Only, fresh off the action on Monthax (the setting for Ghostmaker). As the forces begin to filter in to the city, an atomic explosion marks the demise of Vannick Hive, to the north.
The new forces quickly factionalize. Gaunt, along with the leaders of Guard units from Roan and Narmenia and some of the planetary guard, advocate probing the Ferrozoica lines with an armored assault, while Sturm of the Ghost's rival unit the Bluebloods, supported by the majority of the hive's nobility and Kowle, advocates hunkering down within the walls of Vervunhive. It also quickly becomes apparent that the Ferrozoica forces, far larger than could be expected to be levied, are actually the results of the hive being corrupted by the zealots of Chaos, who have turned the entire hive, men, women, and children, into soldiers. Gaunt receives a request from Lord Chass, a noble who disagrees with the hive's choice of action. At the same time, guild leader Worlin, ordered to cut the flow of oil from fallen Vannick, secretly refuses to do so, killing several of his staff to hide his tracks.
The first major Ferrozoica assault disrupts Gaunt's plans to meet with Chass. During the attack, bizarre mechanized units are fielded by the Zoicca troops; although the assault is repelled, the Vervun forces are shaken by the willingness of the Chaos-tainted forces to pay a heavy price in men. In the aftermath, Gaunt meets with Chass, who evaluates his character, and Ghost medic Dorden teams up with local doctor Ana Curth begin to investigate the deaths caused by Worlin.
The second assault by Zoicca is even more intense than the first, and the defenders are severely hampered by inadequate communications protocols and ineffective, inexperienced commanders. The southern walls almost fall, with reinforcements bottled up by bad coordination, until Kowle is able to gather a relief force. After the battle, Gaunt executes southern salient commander Modile for his cowardly withdrawal from responsibility during the attack. Kowle makes a political power play before the hive government, ordering the trial of Narmenian tank commander Grizmund for damaging the hive in his own attempt to rally to the south during the battle. The allied forces also discover that the Zoicca forces are broadcasting a message identifying themselves as attached to Chaos warlord Heritor Aspohdel, an old foe of Gaunt's.
Gaunt and Kowle, rivals from an earlier campaign, wrangle over Grizmund, culminating in a confrontation at a secret tribunal. Meanwhile, the Zoicca forces' subversion of Vervunhive High Lord Sondar reaches an apex, leading to the lord bringing down the artillery shield that protects the hive. At the same time, Zoicca forces from Vannick enter the rear of the hive through the open pipelines of Worlin. Vervun commander Croe dies on the walls, and second-in-command Anko is obliterated, along with the command post, by a missile strike. The defense quickly collapses, and the hive teeters on the brink.
Gaunt, along with his unlikely allies in the Bluebloods, is spared the worst of the initial assault by the bunker in which the tribunal is taking place, Gaunt frees Grizmund and strips Kowle of his authority. As the group receives reports of the state of the assault, Sturm, now senior commander, orders a retreat and runs off. Gaunt and the remaining Imperial forces decide instead to reactivate the shield. They gather at Sondar's compond, where they meet forces from Croe's command unit and the fatally-wounded Lord Chass. They battle their way through Sondar's defense and reactivate the shield. Gaunt sets up a new command post in an Imperial chapel, and restores order to the defenders. Lord Chass' daughter visits Gaunt and provides him with a secret weapon -- a program designed to disable computer systems.
The fight seems to be stabilizing until the Ferrozoicca forces deploy a giant vehicle dubbed the Stake, which uses a powerful cannon to bring down the city's walls. Intelligence quickly discovers that the Stake is broadcasting the Asphodel chants, which might be serving as a command signal for the Chaos forces. Gaunt gathers the best of his forces and personally leads an attack on the vehicle. Inside, they fight their way to the bridge, and Gaunt uses the program to end the broadcasts, paralyzing the Zoicca forces, The Heritor himself attacks the party, and is killed by Gaunt, although the Heritor manages to severely wound his foe in the process.
In the aftermath of the battle, however, it becomes clear that the damage to Vervunhive is too extensive to allow its survival. The remaining population is asked to found two new hives, although it will take a century or more for the founding to bear fruit. The Warmaster offers disillusioned citizens to join the guard, and thousands do, many requesting posting to the Ghosts. The novel ends with the Ghosts, their damaged leader having barely recovered, embarking to their next war zone.
Best part of story, including ending:
Abnett's prose, as always, crackles, and the structure of the novel, alternating between a historical tone and placing the reader in the action, is quite effective.
Best scene in story:
The interactions between young trooper Caffran and hiver Tona Criid, as the latter tries to take food from the Ghosts to survive, brings the action's impact down to earth.
Opinion about the main character:
Gaunt is still a bit empty, although here, he's given a bit more to work with.