Two kids, living along the same train line north of New York City, connected in ways they do not yet understand ... Myla feels overlooked and invisible. But she thinks her luck will change after she finds a beautiful necklace at a street fair. It's perfect for the first day of middle school. Only that's exactly when her troubles begin. Peter wishes his brother, Randall, would hang out with him instead of with his spray-painting crew. Then one day Randall paints a strange tag that he finds in a book left by their father, who was killed in a mysterious fall. And Randall disappears. When Myla meets Peter, she gets pulled into his mission to find his brother. It turns out her necklace is an important clue—and that dangerous people are after it, and after Randall, too. They will stop at nothing to get what they want. Thrown into a world of parkour moves, graffiti, and missing diamonds, Myla and Peter must race to find Randall ... and uncover a family secret before another deadly fall.