Episode 8 of The Spiderwick Chronicles opens with Dr. Brauer and Helen embarking on a mission to purchase vast quantities of milk. It transpires that the dragons require milk to fuel their growth, an essential aspect of their development. As they depart, Dr. Brauer surreptitiously spikes the beverage of the unsuspecting convenience store employee, transforming her into a mushroom zombie.
Meanwhile, the residents of Henson are succumbing to an unprecedented sleepiness, their eyelids drooping faster than anyone could have anticipated. Mulgarath, now in possession of the dragon page, plots a feast for the following night, unaware of the brewing resistance.
Thimbletack swoops in to rescue Jared, and they reunite with Mallory, her face obscured by a tapestry of mushrooms. She promptly applies the same disguise to Jafred's face, and together they navigate past the zombies undetected.
In the depths of the forest, Jared and his compatriots convene. Jared learns that Simon had feigned treason to infiltrate Mulgarath's inner circle and uncover his sinister plan. Moreover, Simon had stolen the antidote for the sleeping sickness, a potion crafted from the dragon seed that had restored Bree and Hatcher to consciousness. The group devises a daring plan to assassinate Mulgarath with Bree's vorpal sword, as Mallory is unable to wield it. However, Jared abruptly departs, leaving his friends perplexed.
Back at the Spiderwick house, Dr. Brauer dreams of a grand dinner, insisting that Helen dress up for the occasion. Meanwhile, Jared's friends rack their brains for a way to infiltrate the house. Jared reveals that he has a plan, but Simon warns him that his fate is sealed, as Calliope had foreseen. Despite their differences, Simon confesses that while he hates Jared, he also loves him deeply. With heavy hearts but resolved spirits, they embark on their perilous mission.
Simon dragged Jared into the Spiderwick estate, with Jared as his unwilling prisoner. Somehow, they managed to persuade the others that Simon had switched sides, but it was all a ruse. He even revealed the group's cunning plan to dupe Mulgarath. Jared was ushered to Helen, who he implored, insisting that only she held the key to their salvation.
Meanwhile, Simon pleaded with Calliope for assistance, though she had already sensed his deceit. With a clever argument, he somehow swayed her, and she reluctantly handed him the antidote. Helen and Jared hatched a daring plan to flee Mulgarath's clutches through the treacherous Manchineel. Their only obstacle was Helen's memory; she needed to recall the precise method of brewing the tea, else they would perish.
Calliope, having decided to aid Simon, accompanied him to a mysterious locale where they summoned the sprites, beseeching them for assistance in vanquishing Mulgarath. Elsewhere, Bree and Malory stumbled upon the hidden Field Guide in the attic, but their discovery was not without consequences. A mushroom zombie, revealed to be Bree's father, Tanner, had also discovered their secret.
At dinner, Helen and Jared successfully invoked the recipe in time, rendering them invisible. In this state, they traversed both the real and spiritual realms, encountering Lucinda, their silent guardian. She bade them farewell, urging them to seek her father in the Seelie Court.
Back at the house, Bree's attempts to vanquish Mulgarath faltered, but Mallory rose to the challenge, wielding the sword to protect her. As they engaged in a fierce duel, Jared frantically deciphered faerie language, seeking to summon the troll. Mallory unexpectedly joined their ranks, thanks to Helen's timely spraying of iron on Mulgarath's face.
They returned to Jared's location, the trio peering through the window and whistling, striving to replicate the haunting melody of the wind through the trees. As Mulgarath strode into the room, he was suddenly seized by a colossal, stretchable hand belonging to the troll. Its form remained cloaked in shadow, never fully revealed to their eyes.
Concurrently, the sprites descend upon the town, sprinkling it with magical powder akin to a waterfall. Gradually, the slumbering townsfolk emerge from their eternal slumber, while the zombies revert to their human forms. Valentina and Lucinda meet once again in this new dawn, and the joy that fills the air is palpable.
The Grace family, accompanied by Calliope, step into their abode to behold a sight that is both startling and surreal. The dragon, resembling a B-movie larva, has hatched and now dominates the space. They consider terminating its life, but Jared's family apologizes for their earlier attempts to alter him, offering him the ultimate decision. Thimbletack, too, undergoes a transformation, evolving from a brownie to a boggart, his eye color shifting as a testament to his change.
After much contemplation, Jared hesitates, but suddenly another Jared appears, insisting that he is the true Jared. To prove his claim, the second Jared touches iron, and Mallory seizes the opportunity to stab the first Jared, who is now revealed to be Mulgarath. With a gasp, he vanishes.
The second Jared, now unmasked, embraces his family, revealing a scar on his hand - a telltale sign that he was Mulgarath in disguise. Meanwhile, the real Jared finds himself transported to the enchanted realm of fairies, where he encounters his esteemed great-grandfather, Arthur Spiderwick. The reunion is emotional and profound, marking a new chapter in Jared's adventure-filled life.
