When Millie's grandpa falls ill, she and her new puppy Travis have to stay with her aunt while her parents take care of him. At first Millie is glad to have Travis there to cheer her up, but a long period of rain and thunder at the riverside cottage soon leaves him terrified. Then just as Millie and Travis begin to settle in, the heavy rain floods the neighbourhood, with Travis stuck at home all on his own. Will anyone be able to rescue him in time?