Tessa Gordon is a regular kind of schoolgirl in the small town of Lakeside - but her experiences are far from regular! Her curious nature and adventurous spirit seem always to lead her into strange, often scary, events. In this story, Tessa and her friends Anna and Kim go to the coast on their annual school trip. Also part of the expedition are their rivals, the gang of boys led by Danny 'Dog's Breath' Dorman. When the children go to sea in the large fishing boat, the Wave Rider, little do they know that they're about to encounter intergalactic adventurers.Join the children in this mysterious adventure and see how they find a way to help the aliens solve a very big problem.