'Truly the smartest and funniest book about spontaneous combustion you will ever read' JOHN GREEN, #1 bestselling author of THE FAULT IN OUR STARS A TIME magazine Top 10 YA Book of 2016! Mara's senior year is proving to be a lot less exciting than she'd hoped, until the day - KABAM! - Katelyn Ogden explodes during third period. Katelyn is the first, but she won't be the last senior to explode without warning or explanation. The body count grows and the search is on for a reason, while the students continue to pop like balloons. But if bombs or terrorists or a government conspiracy aren't to blame, what is? With the help of her oldest friend, her new boyfriend, a power ballad and a homemade disco ball, will Mara make it to graduation in one piece? It's going to be one hell of a year, where the only test is how to stay alive and where falling in love might be the worst thing you can do ...