Episode 2 of The Spiderwick Chronicles opens with Mulgarath disguised as Dr. Brauer attempting to conduct a therapy session with Jared, but Jared's distrustful gaze remains fixed on him. Just as Calliope enters the room, Jared catches a fleeting glimpse of Lucinda within her, a fleeting vision that leaves him unnerved. Suddenly, Helen rushes in with startling news - Lucinda has vanished from the hospital, leaving a mystery in her wake.
The truth, however, is far stranger than anyone could imagine. Lucinda, ever the curious one, had concocted the invisibility potion she'd always talked about and embarked on a journey of invisibility. Helen, Jared, Dr. Brauer, and Calliope hurry to the Spiderwick mansion, where Calliope stays with the children while Helen and Dr. Brauer join the frantic search for Lucinda.
Jared leads the party to the attic, sharing his encounter with the mysterious being that haunts the mansion. As they listen intently, the familiar, unsettling noise echoes through the rafters. Jared is determined to capture the creature, and they spread flour on the floor to trace its footsteps, setting up mouse traps that Mallory scowls at in dismay.
Amidst the tension, Jared notices the growing closeness between Simon and Calliope, causing him to withdraw to his room. When Simon seeks him out, Jared confesses his fleeting vision of Lucinda in Calliope's form, adding to the mystery surrounding their missing friend.
Meanwhile, Lucinda strides confidently into a local convenience store, asking for directions to the Goblin Market. After a cautious inspection by the clerk, he ushers her through a hidden door that leads to the wilds.
Back at the mansion, Jared sets up a DIY surveillance system, determined to solve the mystery. Suddenly, the fire alarm blares, and Jared rushes to his room to find his bed engulfed in flames. The page containing information about the ogre is reduced to ashes, leaving Jared more perplexed than ever.
Elsewhere, Mallory practices fencing near the trees, relaxing and closing her eyes. But in the blink of an eye, her hair is magically tied to the staircase railing. Accusing Jared of the prank, Mallory's anger is fierce despite his denials.
When Simon and Calliope venture to the kitchen to find something to untangle Mallory's hair, they stumble upon a chilling discovery - Simon's pet mice, frozen solid in the freezer. The accusations fly again, with Simon and Mallory pointing fingers at Jared, citing his past "pranks" as evidence of his guilt. Jared, in their secret language, confides in Simon that he suspects Calliope is behind the string of mysterious events, but Simon remains uncertain.
As the tension mounts and the mysteries deepen, the Spiderwick Chronicles take a turn for the even more fantastical and perilous.
Simon and Calliope solemnly buried the mice, with Calliope's warmth towards Simon and his emotions evident in her every gesture. Meanwhile, Jared was busy poring over surveillance footage, determined to unmask the culprit. He stumbled upon a shot, but it was blurred, frustrating his efforts.
Later, they all gathered as Jared announced that he had somehow managed to sharpen the image. Their eyes were glued to the footage, eager to discover the truth. But to their astonishment, it was Jared himself in the picture, igniting the blaze by burning a picture in his room. The accusation was instant; everyone believed Jared was behind the mischief.
Simon, however, sought out Jared to talk. Jared vehemently denied any harm towards Simon, swearing his innocence. Suddenly, a noise emanated from behind the bookshelf, piquing their curiosity. Jared peered through the shelves in search of clues, while Simon inadvertently stumbled upon a hidden staircase leading to Arthur Spiderwick's study.
Inside, Lucinda was locked in a heated argument with an enraged Thimbletack, the boggart. Jared and Simon introduced themselves, but Lucinda was cautious, touching Jared's neck with an iron knife to ensure they weren't Mulgarath. Once satisfied, she revealed the secrets of her father's Field Guide, a tome offae knowledge torn apart and hidden in vaults across the city, each guarded by a unique magical puzzle.
She implored them to use this knowledge to destroy Mulgarath, warning that if the information fell into his hands, he would use it to slaughter everyone and rule the magical realm.
Later, Helen and Dr. Brauer returned to the mansion. Before departing, Lucinda handed Jared a hollow stone, a souvenir from the Goblin Market. Dr. Brauer escorted Lucinda away, presumably back to the hospital. In the car, she confessed to Helen that she had recognized Mulgarath and marveled at Calliope's ability to change her appearance at will.
They drove to a secluded forest path where Lucinda faced Mulgarath. She refused to divulge the location of the Field Guide, explaining that her memory had been erased. Mulgarath stabbed her, but Lucinda transformed into a burst of laughing flowers, leaving him baffled. And so, Episode 2 of The Spiderwick Chronicles drew to a close.
