I Know Your Secret — Daphne Benedis-Grab

"A compulsive middle grade thriller." -- Book Riot
The email arrives Sunday night: Do exactly what I say, when I say it, or I will reveal your secret.

On Monday morning, seventh graders Owen, Gemma, Ally, and Todd, who have nothing in common and barely know each other, must work together and follow the instructions of an anonymous blackmailer. None of them want to go along with the blackmailer's strange instructions, but each of them have a secret they must protect at all costs.

Set during a single day of school, the students race against the clock to complete a unsettling list of tasks. They'll do whatever it takes to keep their secrets hidden . . . but when they discover what the blackmailer has in mind, they realize things may have just gone too far. Can they put a stop to the plan, or is it too late?