Harvey is a ten-year-old boy living in the muddy town of Millsap who desires adventure. When a strange visitor offers him a trip to a magical resort, his bold nature leads him to accept. He possesses a strong curiosity that drives him to explore the shifting seasons of his new environment, even as he begins to notice frightening details hidden behind the fun.

Rictus is a tall, yellowish man with an unnaturally thin frame who wears a fancy suit and spectacles. His most prominent feature is an exaggerated smile that exudes a false sense of cheer. He serves as a fast-talking recruiter, traveling to the outside world to lure bored children with promises of endless fun.

Mr. Hood is the mysterious and deeply private owner of Holiday House. He remains unseen by the visiting children, managing the magical estate and its rapidly shifting seasons entirely from the shadows. His supernatural servants carry out his wishes to ensure the guests remain entertained and satisfied.

Lulu is a freckled girl with long frizzy blonde hair and huge blue-green eyes. As the longest-residing child at Holiday House, she possesses a room overflowing with toys but remains strangely melancholy. She frequently wanders the grounds in a trance and spends much of her time staring into a dark lake.

Wendell is a bespectacled boy who thoroughly enjoys the endless games and rich food at Holiday House. He ignores the magical peculiarities of the estate, choosing to focus on immediate pleasures rather than asking questions. He serves as an eager playmate for Harvey, preferring action and fun over investigation.

Mrs. Griffin is the ancient cook at Holiday House, characterized by wispy hair and a face resembling rolled-up cobwebs. She provides the visiting children with plates of delicious food and gentle maternal care. Despite the joyous environment she helps maintain, she harbors a deep underlying sadness and quietly hints that things are not perfect.

Jive is one of the magical servants operating the estate alongside his siblings. He possesses a frantic nervous energy, with muscles constantly in motion and hair that writhes anxiously. He encourages visiting children to indulge in mischievous behavior and practical jokes.

Marr is a grossly fat, toothless woman whose flesh barely clings to her bones. As a resident of the property's roof, she possesses the magical ability to mold and reshape a child's physical form like soft clay, creating frightening costumes for their entertainment.

Carna is a terrifying flying beast kept hidden on the roof of the estate. It possesses rotted skin stretched over barbed bone and a throat full of snaky tongues. Its jaws are set with hundreds of sharp teeth, functioning as a lethal deterrent against anyone breaking the property rules.

Clue-Cat is one of the resident felines living at the estate, known to the cook as the wicked one. The cat roams the kitchen freely, enjoying the warmth and spilled milk until a sudden accident occurs near the stove.

Blue-Cat is a blue-furred feline living comfortably at the magical resort. The cat frequently rests in warm spots and observes the children as they wander through the confusing hallways.

Stew-Cat is the third magical feline residing at the resort. The cat is loyal to the kitchen staff and occasionally acts as a guide to the estate's hidden areas when children require assistance.

Harvey's father lives a mundane life in the muddy town of Millsap. He loves his son deeply and previously carved a highly detailed wooden toy ark that remains one of Harvey's most cherished possessions.

Harvey's mother worries about her son's severe boredom during the dreary winter months. She agrees to let him take a spontaneous vacation, hoping the change of scenery will improve his spirits.