A young American girl with a unique affinity for insects is sent to a remote Swiss boarding school. Shortly after her arrival, the school is beset by a series of brutal murders, terrifying the students and faculty. With the local law enforcement struggling to make sense of the gruesome killings, the girl's peculiar talent provides an unexpected form of insight. Feeling disconnected from her peers and struggling to adapt to her new environment, her ability to communicate with insects slowly becomes central to the mystery. As she navigates the complexities of school life, her connection to the natural world deepens, and she finds herself drawn into the macabre happenings that continue to unfold around her.

Working alongside a wheelchair-bound entomologist who sees the potential in her gift, the girl begins to harness her affinity with insects to aid in the investigation. The scientist, together with his chimpanzee assistant, provides support and friendship, giving her the confidence to employ her skills in search of the truth. As the investigation progresses, the pair discovers that the key to solving the murders may lie in an understanding of the behavior of a rare species of fly that is found at the scenes of the crimes. With time running out and the killer still at large, the girl must uncover clues from the natural world to stop the violence and reveal the dark secrets hidden within the school.