The series tells the story of Fishtronaut, a fish in a spacesuit, similar to reverse scuba gear, which allows him to fly and breathe out of water. He is a secret agent who, along with his friends Marina and Zeek, unravel the mysteries occurring in the Smiling Trees Park. They solve the mysteries with the help of a P.O.P. (Primary Objective Pod), a magical multicolored ball containing clues vital to the mission.
