A secret war is raging between the wizards of The White Council and the vampires of the Red Court. After attacks in Palermo, Sicily and the Congo decimate the ranks of the Wardens, the Council is desperate enough to promote Harry Dresden and place him in charge of a team of junior recruits on a secret mission to Iowa to extract a small group of mortal scholars who assist the Council. They reach the scholars just before night falls, forcing them to barricade their house against an army of vampires. Their initial assaults on the house are beaten off, but Harry knows that both time and numbers are on the enemy's side. Harry senses something wrong; if the vampires wanted the scholars dead, they could have destroyed the housefrom a distance. Eventually, one of the scholars admits that a Shoggoth is imprisoned in the cellar - a monstrous servant of the Old Ones that, among other things, wiped out the Akkadian civilization and devastated Hammurabi's capital of Babylon. Grimly, Harry recognizes the Shoggoth as a "supernatural weapon of mass destruction", that the vampires want to capture, despite the fantastic danger to the entire world. The vampires' next assault almost overwhelms the defenders, until Harry's half-brother Thomas Raith appears behind the vampires and kills several of them, before retreating inside the house. He warns Harry that his own clan, the White Court, has sent a force of human auxiliaries to assist the Red Court's leader, Baron Bravosa. This makes the situation even more serious, since the First Law of Magic forbids wizards from using lethal force against other humans. A mortal servant of the vampires infiltrates the house and kills several of the scholars, opening a hole in the defense. Harry, who grimly reminds his proteges that he "plays to win," releases the Shoggoth. The vampires hold it at bay with flamethrowers, and Harry sends the scholars to safety, escorted by the three junior Wardens. When the vampires' fuel runs out, Harry and Thomas lure the Shoggoth to a nearby quarry. Harry is attacked by Baron Bravosa, who taunts that Harry is no match for him, even if he weren't exhausted and badly wounded. Harry knows he doesn't have to be: a minor spell is enough to nudge Bravosa into the grip of the oncoming Shoggoth, and the vampire dies screaming in agony and begging for help. Once the monster is inside the quarry, Harry and Thomas plant and detonate explosives, destroying it. Leaderless, and deprived of their objective, the vampires retreat. Harry reunites with his team, and their elation at having survived and triumphed over the odds is tempered by the knowledge that only an extremely powerful wizard could have imprisoned the Shoggoth on the mortal plane, which means someone from the White Council, their own side, has not only violated the Laws of Magic, but sent them to protect it in the expectation that they would die. Elsewhere, a shadowy figure receives a phone call about the destruction of the Shoggoth, and comforts his caller by saying there are many other similar weapons they may use for their purposes.
