Agatha Armstrong and her trusty sidekick Mrs. Mac were once the world’s most daring adventurers. But when her son Ant came along, everything quickly changed and her devil-may-care ways took a backseat to being over-protective and terrified of anything that posed a risk to her family.

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.