Shelby Holmes is not your average nine-year-old. For one, she happens to be the best detective her neighbourhood has ever seen, using her uncanny analytical mind and sassy attitude to solve crimes which stump even the police department. But when eleven-year-old John Watson moves in to her block of flats, Shelby finds a solution to the one puzzle that's eluded her up until now: friendship. This dynamic duo find themselves swept up in a dog-napping case that'll take both their talents to crack.