Nora, 12, is small for her age but finally tall enough to ride the Cyclone roller coaster at Coney Island while visiting her cousin Riley. Riley goes on the ride with Nora and then collapses when they get off: an undiagnosed medical condition has resulted in a stroke. Riley ends up in the PICU (pediatric intensive care unit) while Nora, at first scared to see Riley, is spending long hours in the hospital waiting room. Monica, a hospital counselor, and Jack, an experienced kid visitor because of his younger brother’s illness, both help Riley navigate the frightening uncertainty, but she can’t bring herself to tell anyone how guilty she feels. It turns out Riley was terrified to go on the roller coaster so Nora blackmailed her, threatening to tell Riley’s mom about an older guy Riley’s been texting. Nora’s engaging, honest voice and compelling extended family dynamics (achingly real and recognizable, and sometimes funny) propel a story that also captures how strangers step up at times of need. Riley’s slow progress by story’s end is all the more satisfying because it shows how the stroke, for all it has changed what Riley is able to do, especially with regard to speaking, has not changed who she is. (Ages 9-13)