The Flock have barely recovered from their Antarctica adventure before they are pulled into another one. Millions of fish are dying off the coast of Hawaii and something—or someone—is destroying hundreds of ships. The government enlists their help to find out the cause after being unable to themselves. While the Flock is undertaking the task, a criminal mastermind is tracking their every move. Then, Max's mother is kidnapped and is being held in an underground submarine. They must try to save the ocean, Max's mother, and protect themselves from the criminal mastermind's own ideas for them. During the struggles, Fang and Max's relationship makes progress, causing Max to realize the feelings she has for Fang.