When enigmatic freshman Amanda Valentino arrived at Endeavor High, she chose three people - Callie, Hal, and Nia - to guide her through the choppy waters of her new school. Except she didn't tell them about each other. When Amanda leaves, the three must reluctantly work together to figure out why. But once they start piecing together the cryptic clues that Amanda herself is leaving for them, they realize that everything they thought they knew about her is false. The more they dig, the mystery of where - and who - Amanda is deepens.

Hadley Jamison doesn't know what to think when she hears that her classmate, Archer Morales, committed suicide. She didn't exactly know him, but that doesn't stop her from feeling like there was something she could have done to help him. So to Hadley's surprise, on the very night of Archer's funeral, she has a run in with Death himself and is offered the chance to go back in time to stop Archer from ending his life. The catch? She only has twenty-seven days to do it. And if Hadley doesn't succeed? Well, she doesn't want to think about that.