Gray is already bigger than all the other sharks in his clan, or shiver. He can’t stop growing, and when his hunger gets him into trouble, he’s banished from the reef. Luckily his best friend Barkley comes with him… but their hunt for food forces them to journey deep into the dangerous Big Blue. Then Gray and Barkley accidentally swim into Goblin Shiver territory. They have no choice but to join the shiver. They’ll help fight against the rival sharks of Razor Shiver in return for training, protection, and food. But who can Gray and Barkley trust when the ocean is full of slippery fish?
Ever since Gray, Barkley, and their friends defeated Goblin, an infamous great white, at Tuna Run, life in the Big Blue has become murkier than ever for this young shiver of sharks. Food is scarce. Enemies lurk in every shadow. And Gray still doesn't know what has become of his family - of his mother, Sandy, and the rest of his Coral Reef shiver. Everywhere they swim, currents seem to whisper of a growing threat... of a shark who will stop at nothing until he has seized control of the entire ocean.
Gray and his alliance of peaceful shivers - Riptide, Coral, and AuzyAuzy - have beaten the bloodthirsty emperor Finnivus and his vicious Indi Shiver Armada to smithereens, sending them swimming as fast as they can retreat. But there’s no time to party: Finnivus may have been humiliated, but he’s still out for revenge. This is the ruler who feasts on the heads of every shark he conquers, after all. When the emperor’s gangs of soldier fish strike, Gray and his friends endure a tragic loss.