A Desperate Wizard and a Royal Summons
Harry Dresden is at rock bottom: broke, depressed, and unable to pay rent after his girlfriend, Susan Rodriguez, left. His apartment is a mess, and his relationships with friends like Karrin Murphy are strained. Just as he considers desperate measures, Mab, the terrifying Winter Queen of Faerie, appears in his apartment with her knight, Lloyd Slate. Mab offers Harry a deal: solve the murder of the Summer Knight, Ronald Reuel, and prove her innocence. In return, she will release him from the magical oath his faerie godmother, Leanansidhe (Lea), holds over him. Harry is wary of Faerie politics, but the promise of freedom from Lea's control is strong, and the threat of his apartment building being foreclosed adds to the pressure.
The Summer Court and a Dire Warning
Harry accepts Mab's offer and travels to the Summer Court, where he meets the Summer Lady, Lily, and her knight, Fix. The Summer Court is in chaos, preparing for war against Winter, believing Mab is responsible for Reuel's death. Harry learns that Reuel's death has created a power imbalance, threatening to plunge the mortal world into an endless winter. He also discovers that the Summer Knight's role passes to the next eligible male and that Fix, the current Summer Knight, struggles with the power. Harry is warned that war is near and that he is a pawn in a much larger game, caught between the two powerful Faerie courts.
Tracking Down the Truth
Harry begins his investigation, first examining Reuel's body in the morgue, where he finds unusual magical residue. He asks for Karrin Murphy's help; despite their recent tensions, she agrees. Their investigation leads them to shady individuals involved in dark magic, and they uncover evidence of a powerful, unfamiliar magic. They discover that the murder was not a simple act of aggression between the courts, but something more sinister. During their search, Harry encounters the terrifying presence of Mavra, a powerful Red Court vampire he previously fought, hinting at a larger conspiracy.
A Deadly Confrontation and a New Ally
Harry and Murphy track the magical residue to a warehouse, where they confront Mavra and her followers. A fierce battle ensues, during which Harry is severely injured. During the confrontation, Harry's half-brother, Thomas Raith, a White Court vampire, unexpectedly helps Harry and Murphy escape. Thomas reveals he is also investigating Mavra, as her actions threaten his own interests. Despite their complicated history, Harry reluctantly accepts Thomas's help, recognizing the seriousness of the situation and the power of their shared enemy. This alliance, however, is full of mistrust, and Harry remains wary of Thomas's true motives.
The True Nature of the Murder
Harry, with Thomas's help, examines the magical evidence. They discover that Reuel was not simply killed, but his soul was removed and replaced with something else, a process needing immense power and specific dark magic. This method points away from a simple Faerie assassination and toward the Red Court vampires, specifically Mavra, known for such rituals. Harry realizes that the Red Court is trying to destabilize the Faerie Courts and exploit the resulting chaos, using Reuel's murder to start a war that would weaken both sides.
The Geas and Lea's Betrayal
As the investigation continues, Harry realizes the magical oath placed on him by Lea is not just a simple compulsion. He discovers that Lea herself is involved in the plot, acting as a double agent or being manipulated by Mavra. Lea's actions, initially seeming helpful, have actually been guiding Harry into dangerous situations, furthering Mavra's plan. Harry confronts Lea, who, under pressure, reveals parts of the larger scheme, hinting at a powerful artifact and the Red Court's true goal. This betrayal by his godmother deeply affects Harry, making him question his understanding of trust and loyalty in the supernatural world.
The Looming War and a Desperate Plan
With the Summer and Winter Courts on the brink of war, Harry knows he must act quickly. He learns that the war is set to begin at a specific location, a nexus of power where the balance between the seasons will be decided. Harry realizes that simply exposing Mavra's involvement will not be enough to stop the war, as the Faerie Courts are too set in their animosity. He plans a desperate move to expose the Red Court's manipulation and force a truce, even if it means putting himself in extreme danger. He aims to use the upcoming battle to reveal the truth.
The Battle for the Balance
The war erupts at the chosen location, a massive clash between Summer and Winter forces. Amidst the chaos, Harry, Thomas, and Murphy confront Mavra and her Red Court vampires, who are trying to manipulate the seasonal balance for their own gain. Harry uses his wits and magic, alongside Thomas's vampiric abilities and Murphy's tactical skills, to fight through Mavra's forces. The battle is brutal, with many casualties on all sides. Harry must fight the vampires and navigate the ongoing Faerie war, trying to prevent either side from gaining a decisive, destructive advantage.
The Mantle of the Summer Knight
During the climactic battle, Fix, the current Summer Knight, is overwhelmed by the immense power of his role. He struggles to control the raw magical energy, putting himself and those around him at risk. Harry realizes that Fix is not strong enough to wield the power effectively and that the role needs a stronger, more stable wielder to restore balance. This realization forces Harry to make a difficult decision, understanding that the proper transfer of this power is critical to preventing an ecological catastrophe and restoring order to the Faerie Courts. The fate of the seasons depends on this power change.
Sacrifice and Resolution
Harry, seeing Fix's struggle and the dire consequences, realizes that the only way to save the balance is for him to temporarily take on the role of the Summer Knight. He makes the ultimate sacrifice, knowing the immense burden and danger it brings, but understanding it is the only way to stop Mavra's plot and prevent the world from plunging into eternal winter. With the role, Harry gains immense power, which he uses to defeat Mavra and restore the balance between Summer and Winter. This act, while temporary, fundamentally changes Harry and his relationship with the Faerie Courts, solidifying his role as a key player in the supernatural world.
Aftermath and New Beginnings
With Mavra defeated and balance restored, the Faerie Courts withdraw, and the immediate threat of war subsides. Mab fulfills her promise, releasing Harry from Lea's oath, a freedom he has long wanted. However, the experience leaves Harry deeply changed, and he now carries the weight of having wielded the Summer Knight's power. He faces the daunting task of rebuilding his life, personally and professionally. While he has achieved a major victory, new threats and challenges are already on the horizon, hinting at the ongoing struggles he will face as Chicago's only professional wizard.