On the surface, the black lagoon looks peaceful. But dip beneath and a murky world of twisted mangrove roots and seagrass beds is revealed. A dark realm of freakish killers waiting to unleash bursts of speed. The otherworldy Mantis Shrimp has spears for arms. Eels make lightning fast strikes with their alien jaws. And a Bullshark’s stolen meal leads to a feeding frenzy of Blacktip sharks. There’s a lot more happening here than the calm veneer suggests.