Brady Hart has learned his lesson: leave crime fighting to the professionals. But what will he do when he discovers a new smartphone app luring kids into unsafe activities? Brady's friends, Sunday and Gladiss, have already downloaded the FROOM app, and their rankings are soaring. Connecting with hundreds of new people is exciting, but the flashing dare button has them all concerned, especially after it results in a serious accident on Christmas Day. Who issues the dares, and why are they targeting kids? Is it just a popularity game or is something sinister going on? Should Brady alert Special Agent Max Dunham or will that get him grounded until summer? The answer seems simple--stay out of it--until a problem bubbles up that boggles his mind: Why has Gladiss changed her appearance, and why has she gone from annoying him to ignoring him