Piers hears from Dr.Tony Heyes, retired physicist and inventor, about what he calls the Adams Event, a time 42,000 years ago when the Earth's magnetic field flipped. During this period, our magnetic shield dropped to below 6% of its current level exposing surface life to dangerous radiation from space and auroral activity so bright that night turned into day. He suggests the extinctions of Australia's megafauna and neanderthals may have been caused by this apocalyptic environmental crisis, as revealed in the rings of an ancient Kauri tree, preserved in a swamp in New Zealand.