New York Times bestselling author C.J. Lyons makes her YA debut with a fast-paced thriller sure to keep readers guessing to the very last page. The only thing fifteen-year-old Scarlet Killian has ever wanted is a chance at a normal life. Diagnosed with a rare and untreatable heart condition, she has never taken the school bus. Or giggled with friends during lunch. Or spied on a crush out of the corner of her eye. So when her parents offer her three days to prove she can survive high school, Scarlet knows her time is now... or never. Scarlet can feel her heart beating out of control with every slammed locker and every sideways glance in the hallway. But this high school is far from normal. And finding out the truth might just kill Scarlet before her heart does.