Follow the wildly imaginative adventures of Esme as she leaves behind her circus home for the first time to spend the summer with her cousins Magnus, Cosmo and Gus at Maclinkey Castle where it's easy to get lost and where you can discover all sorts of weird and wonderful animals in unlikely places - there are porcupines in beds, lizards in drawers and giraffes on the loo. It's all a little wonderful and a lot overwhelming and when her pet donkey, Donk, turns up in a parcel sent from her parents, the fun really begins.
When hundreds of baby penguins hatch in Esme's top floor bedroom, the children have to figure out how to get them outside. Esme and her cousin have the ingenious idea of building a helter skelter around the castle turret, but this is just the start - soon Maclinkey Castle is turned into a full-on Fairground Circus with a big wheel, Bumper Bears, and the show stopping Flying Tigers starring Esme herself!