A brother and sister who befriend a badly sunburned dolphin separated from his family and uncover a secret plan that could destroy the beach and their new friend's home. The kids must devise a clever plan to stop the bad guys, protect the sea life, and, most importantly, save their best friend, Bernie.

The kids are thrilled that Bernie has come back. But so has their old enemy Winston, who's about to kidnap the talented dolphin. Kevin and Holly must rescue their splashy friend before it's too late.