Filling in for George Noory, John B. Wells was joined for the entire program by British astronomer Dr. David Darling for a discussion about some strange ways our world could be brought to a 'megacatastrophic' end. According to Darling, a likely population-ending scenario involves a biological pandemic, something similar to the Plague. "There's a real problem that [a virus or bacteria] is going to develop total drug resistance... and be highly infectious as well," he said. Darling estimated that a highly-virulent, untreatable infection could wipe out half of the people on the planet in weeks.

Darling reported on a possible nanotechnological nightmare known as the 'gray goo' scenario, in which self-replicating, microscopic robots evolve past their programmed purposes to consume all matter on Earth, as well as what would happen should the Yellowstone supervolcano explode. Such an eruption would have 10,000 times the destructive force of Mount St. Helens, he revealed, noting that a minimum of 1,000 cubic kilometers (a box six miles across on each side) of material would be thrown into the atmosphere. North America would be buried under feet of ash and virtually uninhabitable, Darling said. "It will erupt again... this is a certainty," he added.

In light of an asteroid due to pass by Earth next February, Darling speculated on what could happen if a space object about 50 yards across entered the planet's atmosphere and exploded above a major city. It would have the force of many Hiroshimas and destroy much of the area, he explained, likening it to the Tunguska event of 1908. Darling also talked about threats from a forthcoming ice age, explosions on the Sun that could wipe out our technology and set us back decades, as well as direct computer-human connections and how software viruses may one day infect our brains.