Siblings Piper and Percy are young pirates, living on a pirate ship with their pirate mother and father. Every day is an exciting new adventure, sailing the high seas! Piper and Percy are excited to meet their mother's old friend, Seahawk Sally, and her son, Pennington. When the pirate kids happily board Sally's multicoloured ship, they encounter a Pennington who is less than friendly. Will they end the day without the new matey they had hoped to make?