Doodle and her best friend go on another adventure together, this time when they go swimming in the sea. They encounter many surprises during their trip to the sea, and some that take Rosie by complete surprise! The two best friends go and spend the day at the beach to play in the sea, but it is a chance for Doodle to show Rosie two very big secrets. 'As Doodle was swimming away from Rosie, Rosie noticed the strangest thing... Suddenly, the splashes of Doodles kicks turned into gentle, calm little movements and waves which were swaying peacefully behind her.' Although Doodle has Rett Syndrome, it does not mean she cannot live a life like anyone else. She enjoys swimming as it gives her the opportunity to use her legs, which she finds difficult to do on land. Rett Syndrome is a unique genetic condition caused by the X chromosome having an abnormality. This then causes the brain to develop slightly dissimilar to other brains, which could leave some people without any speech and the ability to walk.