';Guaranteed free of unicorns and princesses, it's fun, empowering fiction for 5-8 year olds.' David Nicholls, author of One Day ';Every young girl should read this series!' Amanda Holden ';I loved learning about how the ocean is in trouble.' Tess, age 6 Join best friends Katy, Cassie and Zia on a series of amazing adventures as they work together to save the planet On the hottest day of the ye...