When Kits arrives at Clynton Court School in a grocer's cart, she instantly stands out from her prim classmates. But her spunky personality and sense of adventure soon win her friends among "the Crew" — a group of fun-loving girls.

As Kits adjusts to boarding school life, she finds herself embroiled in mysteries involving stolen exam papers, a hermit's missing cat, and secret tunnels in an abandoned coal mine. With her loyal friends by her side, Kits must use her wit and courage to uncover the truth, clear an innocent friend's name, and prove herself as more than just the girl who came to school in a delivery cart.