The Mage tells an 11-year-old Simon Snow he is the Chosen One and brings him to Watford School of Magicks.

A goblin disguised as a taxi driver tries to kidnap Simon on his return to Watford; Simon kills it with the Sword of Mages.

The Mage orders Simon to leave Watford for safety, but Simon defies his headmaster and refuses to go.

Agatha breaks up with Simon, refusing to be treated as the prize awarded to the Chosen One at the end of the story.

The ghost of Natasha Pitch appears to Simon with a message: her killer walks free, and a man named Nicodemus can bring her peace.

Baz returns to Watford, and Simon reveals the message from Natasha Pitch's ghost, shocking his rival with the news.

Simon and Baz swear a magical truce and pledge to work together until they find Natasha Pitch's killer.

The Humdrum sends a dragon to attack Watford; Baz uses a nursery rhyme to drive it away while Simon channels magic into him.

Simon and Baz track down Nicodemus in a London bar, but he only reveals that a mage hired the vampires who killed Natasha.

Overwhelmed by grief and guilt, Baz sets a forest on fire in a suicide attempt; Simon saves him with a kiss.

The Humdrum attacks the Pitch estate and forces Baz to attack Simon; Simon heals Baz by pouring his own magic into him.

Penny, Baz, and Simon discover that Simon's uncontrolled magical surges created the dead zones, strengthening the Humdrum each time he uses power.

Baz returns to the numpties alone; Nicodemus rescues him and reveals the Mage hired both the numpties and the vampires who killed Natasha.

Ebb sacrifices herself to save Agatha from the Mage; Simon gives all his magic to the Humdrum, making it disappear.

Penny amplifies Simon's voice into a spell; his desperate plea for the Mage to stop hurting him kills the Mage instantly.

Simon Snow arrives at Watford for his eighth and final year as the Chosen One, only to find his nemesis Baz mysteriously absent and his girlfriend pulling away. After receiving a ghostly message from Baz's murdered mother, Simon and Baz forge an unlikely truce and set out together to find her killer. Their investigation leads them to a London bar, a desperate kiss, and the first stirrings of a real relationship before the Humdrum attacks the Pitch estate and a devastating truth about Simon's own power emerges. With the Mage's villainy finally exposed, Simon sacrifices all his magic to destroy the Humdrum, and Penny's amplification spell inadvertently triggers the Mage's death. In the aftermath, Simon and Baz begin building new lives entirely on their own terms, finally free from the destiny that once defined them.

Simon searches Watford's secret passages and grounds for the absent Baz, convinced his roommate is plotting against the Mage.

Baz reveals he was kidnapped by troll-like numpties and kept in a coffin for six weeks before his Aunt Fiona rescued him.

The Humdrum abducts Simon and Penny the previous semester; Penny distracts the entity with its own rubber ball so Simon can carry them to safety.

Simon catches Baz stealing a book from the Mage's office and finds a photo of Baz as a child before he was turned.

The Mage sends Penny's brother Premal to search the Bunce family home, causing Penny's mother to disown him on principle.

Simon shares his magic with Baz in their dormitory room and accidentally conjures a starry sky; the boys hold hands afterward.

Simon visits Ebb the goatherd alone at Christmas and learns her twin brother Nicodemus voluntarily chose to become a vampire.

Simon travels to the Pitch mansion during Christmas break to personally deliver his news about Nicodemus to Baz.

Baz searches Aunt Fiona's belongings and finds a photo of her with Nicodemus in her old Watford yearbook.

Simon returns to the Pitch mansion on Christmas Eve and asks Baz to be his boyfriend; Baz agrees.

Agatha drives to Watford to warn the Mage about Baz, convinced the vampire is manipulating the Chosen One.

Simon arrives at the White Chapel and unknowingly heals the Mage's injury, not yet realizing the Mage has just killed Ebb.

Baz and Penny arrive at Watford; Baz casts a spell only possible for someone truly in love to reach Simon through the magical chaos.

Baz prevents the Old Families from waging civil war against the Mage's allies in the aftermath of the headmaster's death.

Baz graduates top of his class and honors his mother in his speech; Simon surprises him by attending the graduation ball.

Behind the main plot, a series of secondary events shape the novel's world and its relationships. Simon's frantic search for the missing Baz, the Mage's authoritarian raids on Penny's family, and the truth about Baz's kidnapping all expose the growing tyranny lurking beneath the school's surface. During Christmas break, a chain of personal discoveries draws Simon deeper into the Pitch family's world, ultimately leading to his first real relationship and a fragile new sense of identity. When Agatha's misguided warning brings her to the Mage's attention, Ebb's sacrifice and Simon's unknowing act of healing set the stage for the novel's climax. The story closes with Baz averting a civil war, graduating at the top of his class, and dancing openly with Simon at the end-of-year ball.

The secrets, alliances, and surprises behind the main story.

Baz keeps himself alive in the numpties' coffin by thinking of Simon, privately admitting he is hopelessly in love with his rival.

Baz confides to Simon that his father is more upset by his queerness than by his vampirism.

Penny deduces that every war threatening the magical world traces back to the vampire attack on Watford that killed Natasha Pitch.

Baz confesses to Simon that his flirtations with Agatha were only ever meant to irritate Simon, not genuine feelings for her.

Agatha learns from Penny's mother that the Mage once had a girlfriend named Lucy who vanished and may have had a child.

Simon and Baz wake up at the Pitch mansion and discuss their destined fates; Simon confesses he never lets himself think about what he wants.

The Humdrum tells Simon it is not anyone's boy but simply what is left behind after Simon uses his power.

Baz realizes after the Humdrum attack at the Pitch estate that Simon and the Humdrum are somehow the same person.

Simon sprouts red, leathery dragon wings after fleeing the Pitch estate, replacing his earlier feathery angelic ones.

Simon abandons the investigation into Natasha Pitch's murder after discovering his own magic bursts are creating the dead zones.

Lucy's narration reveals she and the Mage snuck into Watford and performed a secret ritual on the autumn equinox to magically conceive Simon.

The Mage reveals over Ebb's body that he is Simon's father and performed a ritual to make Simon the most powerful mage alive.

Agatha moves to California to attend university as a Normal, choosing to escape magical politics and honor Ebb's memory on her own terms.

Baz visits Natasha Pitch's grave after graduation and promises her he has decided to carry on living as a vampire.

Simon, Penny, and Baz settle into a London flat; Simon begins seeing a therapist and the magical world finds peace without a single ruler.

Beneath the surface of the main plot lies a web of private revelations and emotional turning points that define who these characters truly are. Baz's secret love for Simon, Penny's deductions about the Mage's guilt, and Agatha's discovery of Lucy Salisbury quietly build toward the novel's darkest truths. The Humdrum's terrifying confession—that it is nothing more than the echo of Simon's own emptiness—forces Simon to see himself as a threat rather than a hero. Lucy's ghostly account of Simon's magical conception and the Mage's own admission expose the manipulation that shaped Simon's entire life from before his birth. In the end, each character claims a hard-won measure of freedom: Baz accepts his vampirism, Agatha escapes to California, and Simon begins the slow work of healing in a life finally built by choice.