With their first mystery solved and first-day jitters triumphantly behind them, Izzy and her pals---the Solving Mysteries and Revealing Truths Squad---start to settle in to the normal day-to-day at Atom Middle School. Izzy even works up the courage to try out for an all-boys sports team! Things are going well until a mysterious illness threatens to shut down the media center---and maybe the entire school. The S.M.A.R.T. Squad is on the case in a race to figure out what ails them. But that's not all. A pop-up science fair causes excitement and tension for the Squad. And Izzy's failure to speak up in her speech class feels like an obstacle she can't overcome. Can the girls pull together to solve the media center mystery? Will their STEM smarts help them rock the science fair? Or will Izzy Newton's flaws mean the end of the S.M.A.R.T. Squad?