In the hidden depths of Australia’s wild Southern Ocean, a great white shark is savagely attacked one hundred metres below the sea’s surface by a far larger and faster mystery predator.

An electronic tracking device attached to the great white records a high-speed underwater chase, six hundred metres deep, before the shark and its tag are savagely devoured.

Two weeks later, after being carried in the belly of the unknown killer, the still functioning tag is excreted and washed ashore, holding clues that could reveal the identity of the shark’s super predator.

This is the story of a super predator’s epic underwater attack that leads investigators to a mysterious and powerful natural phenomenon that, for a few short weeks each year, attracts the ocean’s most fearsome predators.