A high school overachiever learns one final, important lesson just before graduation.An anonymous texter's threat to post an incriminating picture proving that Myles was at an ugly hazing event-after he'd lied about it to protect his scholarship-turns class valedictorian Myles' graduation day into a nightmarish scramble. In a promised exchange for the file, his nemesis forces him to revisit one by one the scenes of past misdeeds and to get in touch with some of his victims, from a classmate whose beloved teddy bear he stole in third grade to the girl with whom he lost his virginity and then dropped and a longtime friend he likewise ghosted after seeing him blamed for the hazing and expelled. Myles must apologize to each one and acknowledge his wrongdoing. Along with keeping to a low page count and using accessible, straightforward language, McIsaac tells her tale entirely in text messages, which has the effect of ramping up the pace and expertly capturing the troll's taunting tone as well as Myles' increasing desperation as the ceremony approaches. By the end, he has at last identified his tormenter, but more importantly, he's figured out that posting the photo himself-with a short, sincere speech about owning up to failures and taking responsibility for them-is the right thing to do. The characters are minimally described and racially ambiguous.A page-turner aimed at reluctant readers but apt to find a wider audience. (Fiction. 12-18)