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 year, the friends imagine a waterslide coming straight out of Katy’s bedroom window. The slide takes them on a super-slippery adventure like no other, where they meet a host of sea creatures, including a dolphin who shows them why the ocean is in trouble. Now the friends and Thunder must use all their brainpower to help put things right…