Set in the rural Connecticut countryside during the summer of 1935, the story follows twin brothers Niles and Holland Perry, who live with their family on a sprawling farm. The Perry family, still reeling from the recent accidental death of the boys' father, struggles to maintain normalcy despite the undercurrents of grief and secrets that seem to pervade their home. The boys, practically inseparable, share a deep bond, further solidified by their imaginative play and the intricate games they devise. Amidst the picturesque fields and the seemingly idyllic life, there lies a sense of unease, largely due to the twins' mysterious grandmother, Ada, who teaches them about "the game" – a unique ability to project the senses, which becomes a pivotal aspect of the brothers' relationship and the unfolding events.

As the summer progresses, a series of accidents and unexplained incidents begin to disturb the peace of the Perry household and the surrounding community. Initially dismissed as unfortunate mishaps, these events gradually reveal a more sinister undertone, suggesting that not everything is as innocent as it appears. The boys, particularly Niles, find themselves at the center of suspicion and fear, as the idyllic facade of their family life begins to crumble. The strain of secrets, the weight of guilt, and the struggle between innocence and malevolence engulf the family, leading to consequences that irreversibly alter their lives and challenge the perception of reality itself.