What creature would be able to chase down and devour a 500 kilogram great white shark on the sea floor off Western Australia?
But as filmmakers David Riggs and Leighton De Barros began to investigate what dark fate could have befallen the ten-foot monster shark earlier this year, an even bigger mystery unfolded.
Why, once a year, does a rough, remote spot off the WA coast, just half a square kilometre in size, become the epicentre for a barely believable colosseum of battling marine life?