Sierras plans for summer holidays are ruined when her parents force her to stay with an unfamilar cousin in a quiet town. But things become interesting when she stumbles upon a strange robot called the Hydronaut. Hydronaut is more than just a swimming robot; he's super fast and strong and can fly; but he's not alone. With the help of her cousin and a town local Sierra is to help Hydronaut uncover the mystery of his origin while to protecting the town, defeating other robots and learning a new characteristic which robots are not acustomed to. Feelings.