Here, the air they are breathing is under pressure, squeezed down so that there's more gas in every lungful. They have to hope that the rock gives up before they do. With just minutes left, they must take the rock to the surface. “Let's have a look. What have we got?”

 

For Jody, this is the moment of truth.

 

“Hey, there we go. Yep, yep, yep.”

 

He's the first person to see what's hidden deep below the reef.

 

“Yeah, it's definitely coral in there. You can see skeletal structure in here. Yeah, well, this is definitely coral.”

 

And not just any coral, what they've brought back from the depths seems to defy nature. It's a species of coral that can only grow in shallow water. What could possibly explain this?

 

The Earth's orbit is not stable. Over hundreds of thousands of years, tiny eccentricities in its path caused the planet to wobble on its axis. 18, 000 years ago, it was tilted--just one degree, but enough to tip the planet into cold clutches of chaos--an Ice Age.

 

The polar ice caps started expanding aggressively, sucking up water into massive sheets of ice. Oceans dropped in every corner of the world, and the whole shallow sea on Australia's east coast disappeared.