Hollowpox: The Hunt for Morrigan Crow

The third installment in the Nevermoor series follows Morrigan Crow, a Wundersmith, a rare person gifted with the ability to command a mysterious energy called Wunder. Morrigan lives in the Hotel Deucalion, a living, sentient building in the magical city of Nevermoor, as a member of the elite Wundrous Society, whose members recently learned she is the first Wundersmith since Ezra Squall, a mass murderer exiled over a century ago.

On the last day of the autumn term, Morrigan and the eight other scholars of Unit 919 are shown footage from their inauguration night revealing that monstrous creatures lurked behind them, managed by Society operatives. Elder Quinn, one of the Society's ruling Elders, explains that the organization's true purpose is Containment and Distraction: controlling dangerous creatures, many created by past Wundersmiths, while keeping the public ignorant. Morrigan's patron, Jupiter North, helps plan a rare scavenger hunt called Golders Night to distract citizens during an upcoming operation.

On Christmas Eve, Morrigan witnesses the first sign of a coming crisis. While riding the Wunderground train with her best friend Hawthorne Swift and his toddler sister, a leopardwun suddenly reverts to wild behavior and lunges at the baby. Wunimals are sentient creatures possessing human intelligence and language, so this violent reversion is alarming. Morrigan notices the leopardwun's eyes flash glowing green before the creature is subdued and later found comatose.

Meanwhile, Morrigan's education takes a dramatic turn. Mrs. Murgatroyd, the Arcane school's Scholar Mistress, reveals a hidden persona called Rook Rosenfeld, head of a secret School of Wundrous Arts on a sealed underground floor beneath Proudfoot House, the campus building where Morrigan lives. A secret research group introduces Morrigan to "ghostly hours," parcels of preserved time that replay lessons from past Wundersmiths. Using The Book of Ghostly Hours, compiled by her late teacher Professor Onstald, Morrigan begins learning Inferno (fire creation) and Weaving (rearranging energy and matter).

The threat escalates during Golders Night when a bearwun wrestling coach attacks Morrigan with the same glowing green eyes. She barely survives by fleeing through a Tricksy Lane, a geographical anomaly where normal rules do not apply. A third attack at the Nevermoor Opera House sees a horsewun actor trample a performer onstage, and Morrigan accidentally ignites the curtain while breathing fire to intervene.

At a special meeting, Jupiter, now leading a Hollowpox task force, reveals that an aggressive virus is targeting Wunimals, shutting down brain function and leaving victims "hollow": devoid of identity or consciousness. As cases multiply, Morrigan discovers Squall's name was deliberately omitted from The Book of Ghostly Hours and begins secretly visiting ghostly hours featuring him as a boy, finding him a laughing, normal student bearing no resemblance to a mass murderer.

Anti-Wunimal sentiment grows as Laurent St. James, a wealthy agitator, leads a group called the Concerned Citizens of Nevermoor in rallies accusing the Society of harboring dangerous creatures. At the Deucalion's unauthorized Sunset Gala, three Wunimals suffer simultaneous Hollowpox episodes. Morrigan uses Weaving and Veil, the art of shadowmaking, to plunge the lobby into darkness, where she sees the Hollowpox leave its victims as glowing green light before the parasite disperses. She and Jupiter deduce the Hollowpox is a living parasite, possibly created by Squall, that may have originated in the Wintersea Republic. They keep this secret, fearing it would provoke violence against Wunimals.

Squall appears on the Proudfoot House rooftop and offers to destroy the Hollowpox if Morrigan becomes his apprentice. She refuses. He warns that the Society will soon use her as a tool rather than treating her as a threat.

His prediction proves correct. When the Concerned Citizens storm the campus gates and surround Elder Saga, a bullwun Elder, Morrigan channels Wunder through a dead fireblossom tree, reigniting dozens of extinct trees in a spectacular display that stuns the mob. Holliday Wu, the Society's head of Public Distraction, redirects media coverage to this "arboreal miracle." The Elders then leak Morrigan's identity to the press to bury a worse revelation: quarantined Wunimals are permanently losing their speech and intelligence. St. James offers a massive bounty for proof of her abilities.

A new imprint, a tiny flickering flame, appears on Morrigan's finger, marking her mastery of Inferno. It opens the Liminal Hall, a sealed chamber at the end of the underground corridors, where she meets the Kindling, one of the Wundrous Divinities: ancient deities said to have watched over the realm. Manifesting as a vast sentient bonfire, the Kindling accepts her offering of the fireblossom resurrection and grants its seal.

When Sofia, Morrigan's foxwun friend, is struck by the Hollowpox and left catatonic, Morrigan rides the Gossamer Line, a decommissioned magical railway, to the Wintersea Republic. President Maud Lowry reveals the Republic already has a cure and proposes a deal: If Prime Minister Gideon Steed begins diplomatic dialogue, she will share it. Before returning, the train takes Morrigan to Crow Manor, her childhood home, where she glimpses her family but cannot touch them. Back in Nevermoor, Holliday Wu leaks Wintersea's public letter offering the cure, pressuring Steed to accept.

As the crisis worsens, Steed agrees to open the border, announcing Wintersea's emissary as an energy industry leader and creator of the only known cure. Morrigan realizes with horror that the emissary is Squall. A frantic Squall appears at the Deucalion, begging her to prevent the border from opening. He confesses he created the Hollowpox on Wintersea's orders to exterminate Republic Wunimals, but Wintersea weaponized it against Nevermoor to force a diplomatic opening and conquer the Free State.

Squall instructs Morrigan to become a beacon of Wundrous energy, drawing the Hollowpox from every infected Wunimal. The Deucalion grows an overhead glide cable from its rooftop, and Morrigan sails across the skyline as hundreds of green-eyed Wunimals chase her to Courage Square. Fenestra, the Deucalion's fierce feline housekeeper, fights through the horde to stand beside her. Morrigan presses both palms to the cobblestones and unleashes a pulse of fire, lifting every Wunimal into the air. She commands the hovering green lights: "You have to die." They blink out one by one. With no need for the cure, Steed does not open the border.

Morrigan sleeps for two days. She wakes to learn that while the Wunimals in Courage Square recovered, those already in quarantine, including Sofia, remain hollow. Anah Kahlo, Morrigan's healer-in-training unit-mate, reveals the hospital plans to send these patients to zoos. Morrigan summons one of Squall's wolf-shaped shadow creatures by whistling and strikes a final bargain: She will become his apprentice if he cures every quarantined Wunimal. Squall builds a bridge across the Gossamer, the invisible web of energy connecting all things, and works through Morrigan's body to unmake the Hollowpox's damage and restore each Wunimal. Sofia wakes last and says, "Morrigan. Hello."

Squall presents the apprenticeship contract, telling Morrigan she need not sign if she is not genuinely eager. But having experienced the full power of a true Wundersmith and feeling the vast, hungry space it left inside her, Morrigan signs. She returns home clutching Emmett, her childhood toy rabbit that Jupiter retrieved from Crow Manor, and falls into the deepest sleep of her life.