The ocean is something that only a few percent of humans can explore, there are still so many underwater mysteries that need to be known.

You're playing with your dog on the beach, playing throw and catching ball. But the ball you threw went too far, caught by the waves. Your dog doesn't know anything and just follows the direction of the ball until it too is swept away by the waves.

You try to save your dog by getting into the water, the further you are from land the deeper it gets. Just as you're about to reach your dog, something pulls it into the water. Frantically, you dive in and see... a merman?