Mabel lives with her parents in The Mermaid Hotel, by the sea. Mabel likes to keep an eye on the comings and goings of all the guests, particularly their most interesting guest and Mabel's best friend, Madame Badobedah. Madame Badobedah has pirouetted through pyramids, skated across rivers, swum with mermaids and even helped a Triceratops with a toothache.

In this new adventure, the duo set off on a mission to the Natural History Museum. And, just maybe, they will meet a dinosaur along the way.