Taylor Wyatt, Tony Hale, is a widowed father who hopes to sell his house with the help of his sister Liz Wyatt, D'Arcy Carden, a sharp real estate agent. His son Jack Wyatt, Kue Lawrence, is an adventurous gamer, and his daughter Amber Wyatt, Bianca Berry Tarantino, is an aspiring artist who fills her sketchbook with expressive, sometimes unsettling monsters. The family life takes a strange turn when Amber’s artwork seems to touch something unseen.
One day, Jack trips in the woods, breaks his phone, injures his hand, and accidentally drops the device into a nearby pond. When he retrieves it, the phone is mysteriously repaired and his scrapes vanish. Curious, Jack quietly tests the pond’s powers with more items, drawing his sister into the mystery. Amber’s monsters—drawn from her sketches—begin to materialize, and a yellow, bird-dropping-like staining appears on their window, which Jack interprets as a sign that the creatures have crossed from art into reality.
Amber’s creations haunt the town, displaying abilities tied to her drawings, including eyeders—arachnid-eyed figures that quietly steal belongings. One of Amber’s self-modeled monsters breaks into an office supplies shop to swipe markers and sketchbooks, while another monster lands on a school bus, taking the children hostage. Under Amber’s direction, they play soothing jazz on an iPod to lull the creatures; but when a subsequent track shifts to a violent metal song, the monster awakens and gives chase as the kids flee.
Seeking a way to counter the threat, Jack, Amber, and their classmate Bowman, Kalon Cox, reunite in the woods. They explain that the pond can be used to animate weapons and allied creatures that could help defeat the monsters. The trio returns home to find the house damaged and looted by eyeders, and they begin sketching again, preparing for a final stand. After fending off a wave of eyeders, they make their way to the pond, bringing along supplies and, in a personal gesture, Jack hopes to revive his mother by using ashes in the ritual.
At the pond, Amber’s sketches begin to animate and morph into real, living threats. Bowman attempts to stop one of the creatures but is quickly overwhelmed, and the siblings manage to activate their weapons and allies in time, unleashing a coordinated defense against the remaining monsters in town. Amber and Jack reunite with Taylor and Liz, and Taylor pleads with Jack not to throw the ashes into the pond. Yet Jack explains that the ashes are already lost due to a hole in the wooden urn. Ultimately, the family returns to their ordinary lives, forever changed by a night when art and reality collided and the pond’s strange power offered them a precarious balance between danger and hope.
