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 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 and one mistake means you're done for.
Gray asked if he could journey with his Mother, Sandy to the Tuna Run, an yearly event where many Tuna appear and a feeding frenzy occurs - but his mother forbids him. He and barkley drift out into open water when looking for food. Here they meet a shark from the ruthless, Goblin Shiver (previously known as Riptide Shiver). The two sharks return to their homewaters where they are banished for alerting another shiver of their homewaters.
Gray and Barkley swim out into the ocean where they meet Striiker, Snork, Shell and Mari - several sharks banished from their own shivers. They all form their own shiver called Rouge Shiver. Patrols of Goblin shiver sharks catch rouge shiver and bring them to Goblin, the dangerous Great White leader of the shiver and his advisor, Velenka, a sneaky female shark who craves power. Goblin asks Rouge shiver to join
him, which they reluctantey do and train to attack Razor Shiver, a fueding shiver, at the Tuna Run that year. Velenka, who is very curious about Gray, takes him to a cave which is home to a giant megalodon skeleton and reveals her suspisions that Gray is a Megalodon.
When Gray returns to Coral Shiver to visit Sandy, Yappy informs him that Goblin Shiver attacked and killed many sharks and that Coral Shiver is now heady to the Tuna Run.
=====After weeks of training the fight breaks out at the tuna run with many sharks bieng killed by the powerful tuna. Gray catches glimpses of Coral Shiver on the other side of the tuna. Rouge shiver decide together to leave Goblin shiver in the choas and find an ancient ship wreck to call their homewaters just between Coral and Goblin Shiver. Gray informs his friends that he is the last megalodon and then Takiza, an legendary siamese fighting fish appears to offer Gray his training.=====