The Azores. One of the most remote archipelagos on earth.

A marine sanctuary in the middle of the Atlantic, crossed by great ocean wanderers on their extraordinary migrations.

But recently tuna fishermen of one of its smallest islands have had close encounters with a population of large Whale Sharks, completely unknown to science.

Now a team of scientists equipped with special cameras will try to discover what is this mysterious relationship between whale sharks and large schools of tunas.

But as they descend on a submarine towards the deep waters of the Azores, they will have an encounter that will forever change what we know about the life of the largest fish in the world.