A sudden increase in sea surface temperature triggers an alert from the Octonauts' floating sensors, indicating a potential risk of waterspouts. Consequently, they decide to retrieve the devices for safekeeping. However, Kwazii finds himself in a dispute with a territorial triggerfish that has claimed one of the sensors as its home. Soon, both are caught in the swirling vortex of a waterspout. Kwazii then finds himself defending the fish from a hungry seabird and a swordfish. Fortunately, the distinctive grunting sounds the triggerfish emits when distressed allow the other Octonauts to pinpoint their location.