Secrets of the Dragon Sanctuary

This installment of the Fablehaven series follows siblings Kendra and Seth Sorenson as they confront escalating threats from the Society of the Evening Star, a secret organization seeking five magical artifacts that together can open Zzyzx, the great demon prison. The Sphinx, recently unmasked as the Society's leader, has gone quiet but remains dangerous. Kendra and Seth live at home under constant surveillance by bodyguards from the Knights of the Dawn, protectors of the world's magical preserves.

Kendra has been secretly studying the Journal of Secrets, left by Patton Burgess, a legendary former caretaker of Fablehaven, the preserve for magical creatures managed by the siblings' grandparents. Written in a fairy language only Kendra can read thanks to her status as "fairykind," one entry addresses her by name: Patton reveals that he knows the locations of two artifacts but has concealed the specifics in a secret chamber beyond the Hall of Dread, a dungeon corridor lined with cells holding imprisoned spectral beings. He urges discretion, and she tells no one.

At her volunteer day-care job, Kendra is pricked by a stingbulb, a supposedly extinct magical fruit that replicates the first living thing it stings. The day-care supervisor, Rex Tanner, is himself a stingbulb duplicate created to orchestrate her kidnapping. He drugs Kendra while a copy of her, loyal to its creators, takes her place. Seth notices the impostor's strange behavior. Their bodyguard Elise intercepts a letter the fake Kendra mailed to a Society operative, revealing the Chronometer's location at Fablehaven and the existence of Patton's hidden clues. When their friend Warren and Seth confront the impostor, she swallows poison and dies. Seth is devastated, believing his real sister is gone.

The real Kendra is held captive by Torina Barker, a lectoblix who sustains her youth by draining vitality from others. The Sphinx arrives and forces Kendra to touch the Oculus, a crystal sphere that is the artifact of sight. The Oculus grants the power to see everywhere simultaneously but has driven previous users into catatonic states. Kendra's vision expands uncontrollably until she loses all sense of self, but the Fairy Queen perceives Kendra's gaze and commands her to release the crystal, saving her from permanent insanity.

At Fablehaven, the fairy trader Maddox arrives claiming to have escaped the fallen Brazilian preserve. When he enters the dungeon and frees Vanessa Santoro, a narcoblix who can control those she has bitten while they sleep, from the Quiet Box, a cell suspending its occupant in unconscious limbo, his true purpose becomes clear: He is another stingbulb sent to access the secret chamber for the Sphinx. Vanessa, bitter at the Sphinx for abandoning her, turns against the impostor and alerts Grandpa Sorenson. Seth realizes that if the dead Kendra was also a stingbulb, the real Kendra may still be alive. Vanessa identifies Torina Barker, and investigators redirect their search to Monmouth, Illinois.

An unknown ally slips Kendra a knapsack containing an extra-dimensional storage room and a stingbulb. She creates a duplicate of herself, instructs it to guard her secrets, then flees inside the knapsack with Cody, one of Torina's prematurely aged captives. Trask, a Knight of the Dawn staking out the town, finds her and brings her to Fablehaven.

Reunited with her family, Kendra leads the group into the hidden chamber. In the dungeon corridor, Seth discovers he can hear the imprisoned spectral creatures whispering to him. Inside the chamber, Kendra reads Patton's message: The Translocator, an artifact with power over space, is hidden at the Obsidian Waste preserve in Australia, but Patton hid the vault key at Wyrmroost, a dragon sanctuary closed to human interference. Access requires the first horn of a unicorn, which Patton entrusted to the centaurs of Fablehaven. The stingbulb Kendra then arrives with urgent news: The Sphinx has used the Oculus to discover the key's location and plans to send Navarog, a demonic dragon, to retrieve it.

The centaurs refuse to lend the horn, revealing it is protected inside a Tauran maze of invisible, lethally spelled walls guarded by a mountain troll. Seth secretly visits the dying demon Graulas, who explains that a previous adventure left Seth with embryonic powers of darkness. Graulas formally declares Seth a shadow charmer, granting him immunity to magical fear, the ability to see invisible shadow creatures, and resistance to magical emotional manipulation. Using these abilities, Seth infiltrates the centaur stronghold, navigates the invisible maze, befriends the troll, and steals the horn.

Grandpa assembles a team for Wyrmroost: Kendra, Warren, Gavin Rose (a young dragon tamer), Tanu (a potion master), Trask, Dougan (a mountaineer and fellow Knight), and Mara Tabares (a dragon tamer in training). Seth is excluded but stows away inside the knapsack, secretly encouraged by Warren. At Wyrmroost, Kendra guides the team through a powerful distracter spell and opens the golden gate with the unicorn horn. They reach Blackwell Keep, a fortress run by Agad, a wizard who was once a dragon. Agad directs Kendra to Patton's false gravestone, where an inscription reveals the key is an iron egg hidden in the treasury of a secret Dragon Temple.

A stampede injures Warren and exposes Seth's presence. The sky giant Thronis captures most of the team with his griffins, and Seth negotiates their release: Thronis will equip them with adamant-edged weapons and fly them to the temple in exchange for five figurines from the treasury. Separated from the group, Kendra and the injured Warren end up in a gorge. There Kendra meets Raxtus, a small, fairy-raised dragon and son of Celebrant, king of dragons. Raxtus carries Kendra to the Fairy Queen's shrine, where the Queen shows her the route to the temple. Warren, still incapacitated, shelters inside the knapsack's storage room.

The reunited team enters the Dragon Temple and defeats three guardians: the hydra Hespera, the blind dragon Glommus (killed when Vanessa remotely controls Tanu's sleeping body), and the poison dragon Siletta, whose very presence is toxic. Seth proposes using the unicorn horn offensively, reasoning its purifying power should be lethal to a creature made entirely of poison. Handcuffed together so neither can flee in terror, Kendra and Seth press the horn against Siletta while Mendigo, an enchanted wooden puppet serving the team, distracts her. The horn's energy destroys the dragon.

In the treasury, they retrieve the iron egg and figurines. Outside, dragons ambush them. Gavin transforms into an enormous black dragon, revealing himself as Navarog, who murdered the real dragon tamer Chuck Rose and fabricated Gavin's identity to infiltrate the Knights. Navarog swallows Dougan, knocks Mara off a cliff, and slashes Kendra, whose adamant breastplate (a gift from Seth) saves her life. Kendra flees into Sidestep Cleft, a narrow cliff passage, and uses the rain staff, a magical artifact that summons storms, to ground the dragons. Navarog follows in human form, unable to transform in the tight space, and reveals the Sphinx deliberately let the stingbulb Kendra escape so the Knights would send a team including "Gavin" to Wyrmroost. He burns the knapsack, trapping Warren inside. Raxtus, arriving invisibly behind Navarog, strikes and devours him.

Seth fulfills Thronis's bargain and receives two figurines as gifts. Griffins recover the surviving team members. At Fablehaven, Grandpa reveals he has become Captain of the Knights and formally inducts Seth as a Knight. He outlines plans to return the horn to the centaurs, keep the vault key moving to evade the Sphinx's Oculus, and pursue the Translocator in Australia. He then delivers devastating news: The Society of the Evening Star has kidnapped the children's parents.