A man stands steadfast on the bridge, facing a shadowy, beastly silhouette looming on the opposite side. With urgency in his voice, he announces the approaching arrival of the Grace family to the Spiderwick Estate, pleading with the figure to relinquish his daughter. Suddenly, a teenage girl rushes towards him, but his suspicions are piqued by her hasty demeanor. After confirming that she is not his daughter, he inquiries about her identity, to which she responds enigmatically, stating that his question is misplaced. Before he can further inquire, a troll emerges from beneath the bridge, snatching the man and devouring him in a flash. The hideous ogre, previously concealed as the man, transforms into his true form, revealing a ghastly visage.
Episode 1 of The Spiderwick Chronicles introduces us to Helen Grace, the great-granddaughter of Arthur Spiderwick, along with her eldest daughter Mallory and fraternal twins, Jared and Simon. As they relocate to the mysterious Victorian Spiderwick Estate, it becomes apparent that the family's motive is to seek treatment for Jared's troublesome tendencies at the renowned psychiatric hospital under the care of Dr. Brauer. Upon arriving at the enigmatic mansion, they encounter a tree standing proudly in the middle of the hall, planted by Arthur Spiderwick himself. This tree is renowned for its protective powers, warding off evil like an invisible shield. Grace regales them with tales of her Aunt Lucinda's accounts about the tree, explaining that while its fruit is poisonous, a mere few drops can safeguard one from ogres and even grant invisibility.
As they explore the dusty, abandoned house, its quirks and crevices reveal a world of wonder and mystery. Simon eagerly clamors for his own room, but Jared's demeanor suggests a deeper reluctance. Later, Jared confides in his mother about the chasm between him and his brother. He laments that while Simon is adored for his wit and knowledge, he feels shunned and unwanted. He further believes that he is the source of their relocation, a festering wound that plagues the entire family. Despite his despair, Helen reassures him that they will seek the help he needs, though Jared remains apathetic to the prospect.
Deep into the night, Jared was startled by mysterious noises and heavy thumping footsteps. Curious and cautious, he armed himself with Mallory's sword and ventured to investigate. Inside a shadowy cupboard, from whence the sounds seemed to emanate, he poked the air with the sword and was horrified to see blood staining its tip. There, he also discovered a chilling portrait of an ogre, adorned with foreign inscriptions.
Meanwhile, the ogre disguised as a man, later revealed to be Mulgarath in Dr. Brauer's guise, along with the creature posing as Dr. Brauer's daughter, Calliope, sneaked back to the doctor's abode. Here, their sinister plot was revealed: to locate Arthur Spiderwick's Field Guide, annihilate and devour all humans, and establish dominion over all Fae and magical beings.
The following day, chaos reigned at the Spiderwick estate. Simon's beloved pet mice, Lemongrass and Jeffery, had vanished without a trace. The entire family scrambled to search for them amidst the kitchen cabinets, only to be interrupted by Mallory's breathless arrival after a jog. Jared shared his tale of eerie noises and blood-tipped sword, but Mallory was furious that he had used her fencing equipment without permission. Naturally, none of them believed his bizarre tale.
While combing the town, steeped in folklore and legends of fairies, in search of Simon's missing mice, Simon regaled Jared with tales of how the locals celebrated the firefly catching festival, believing that the fireflies were fairies and would grant them wishes. Suddenly, the twins stumbled upon a secret, intricately decorated fairy door adorned with a mysterious little symbol. Jared urgently tried to persuade Simon that they should flee, warning that the house was dangerous, but Simon dismissed his concerns with a scoff.
Back at the house, Helen's mind wandered back to the mysterious incident with Lucinda. She recalled how Lucinda had revealed the secrets of the magical tree's fruit, claiming that a mere few drops could ward off dangerous creatures and even grant invisibility. Lucinda had offered her a cup of tea, but Helen's mother intervened, screaming that it would be fatal for Helen. Suddenly, a realtor appeared, offering to sell the estate, but Helen firmly refused.
Meanwhile, Mallory embarked on her first fencing class in the town, where she encountered a renowned but visually impaired maestro. After a brief mental sparring session, the maestro shook his head, declaring that he could not coach Mallory due to her inflexible approach. Mallory argued passionately, recounting her years of practice since childhood and her grand aspirations, but it was all in vain.
Elsewhere, Jared and Helen visited the hospital for Jared's session. Helen left him to visit Lucinda, while Jared encountered a few peers, Emiko and Hatcher, waiting for their own sessions. After a brief conversation, Jared decided to skip his session and hurried to Lucinda's room. There, he found his mother engaged in a conversation with a silent Lucinda, who revealed her troubled past, including her divorce from Richard, who felt overshadowed by her. When Helen mentioned Spiderwick Mansion, Lucinda's demeanor suddenly changed, and she frantically ordered them to leave.
Elsewhere, Mugarath, disguised as Dr. Brauer, and Calliope visited a museum-like establishment, their eyes fixed on an enamel egg. The employee regaled them with tales of the egg's mysteries, but it was evident from her demeanor that the egg was not for sale. However, Dr. Brauer gave a subtle signal to Calliope, who promptly devoured the egg. Inside, they discovered a mysterious creature, encased in a resin-like substance, that seemed to be moving.
Back at the Spiderwick mansion, the family was gathered around the dinner table, enjoying a peaceful meal. Suddenly, the same mysterious noise echoed through the air, causing Helen to instinctively poke her finger into the wall. Curiosity got the better of them, and they all set to work tearing down the wall to reveal a hidden dumbwaiter, with dead mice dangling from its hooks.
Jared, eager to explore, made a move to climb the dumbwaiter, but Simon quickly intervened. A heated argument erupted, with Simon angrily reminding Jared that their family had been forced to flee their home because of his antics. Hurt and upset, Simon ultimately decided to attend the firefly festival alone. He sent a text to his dad, but received a dismissive reply.
At the festival, Simon managed to capture a firefly, which transformed into a stunning faerie before escaping from the jar, leaving Simon stunned and amazed.
Meanwhile, back at the house, Jared was busy cleaning up. Unable to resist the urge to explore further, he ascended the dumbwaiter into the attic. There, he stumbled upon Arthur Spiderwick's belongings, including a field guide with torn pages. Suddenly, someone began to write on the mirror in front of him: "Click clack, watch your back." Jared turned to see a boggart staring at him with a menacing grin. Terrified, he screamed and ran to alert his family, but they refused to believe his story.
Helen, unaware of Jared's adventure in the attic, discovered that he had skipped his therapy session and was furious. She promptly dragged him to Dr. Brauer's house for a much-needed session, and the episode drew to a close with the family's tensions still simmering.
