Sleepless by Thomas Fahy

Emma Montgomery has been having gruesome nightmares. Even worse, when she wakes up, she isn't where she was when she fell asleep. And she's not the only one. One by one the students of Saint Opportuna High start having nightmares, and sleepwalking. And the next morning one of their classmates turns up dead.

Something is making them kill in their sleep. Emma and her friends need to band together, to keep themselves awake until they can figure out what's behind the murders--before anyone else dies.

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