As the heat of summer really sets in, two members of the Acer Detective Agency head to the bright lights of New York City. On a mission to move her grandfather to Texas, Harley and Rocket plan on filling some moving boxes and maybe taking in a museum or two. The detectives soon learn that the city has more than one secret, and some people may want to keep it that way. The kids find themselves teamed up with an older generation of detectives, as they run from one end of Manhattan to the other, trying to solve one last case. Can the Acer Detectives uncover the clues from a decades old heist, or will this crime become the one that got away