Nina looks at different household inventions and finds out how they work. With the help of her trusty neurons she examines the items to answer children's questions Three friends Jack, Elliott and Lloyd want to know: How does my water soaker work? As ever, help is at hand in the form of Nina and her neurons. Fabulous Felix, the touch neuron, lends a hand as Nina and the boys take a good look inside a water soaker. They then go out and visit a very large and watery invention that uses the same science. In this exciting episode we learn all about pressure and discover how to invent a water soaker of our very own.