A brand-new underwater adventure from the author of the long-running Beast Quest series! Max and Lia are following the evil Professor's trail to rescue Max's father. But when Max doesn't heed Lia's warning about the dangers of the ocean, he ends up getting scooped up in a jetstream. Luckily his friends manage to keep up with him. The stream leads him to another one of the Professor's Robobeasts, Silda the Electric Eel. Max must defeat this foe and recover the second piece of the ancient skull that grants magical powers to Lia and her people. Only then will Max be able to save his dad.