They were pioneering warriors, expert seafarers, and colonists of the North Atlantic realm. The Vikings even claimed in their sagas to have reached America. Now, renowned archaeologist Sarah Parcak uncovers new clues about their legendary expeditions and settlements.

Forty years ago, hundreds of skeletons were unearthed in a mass grave in an English village. Bioarchaeologist Cat Jarman believes these bones are the last remains of the 'Great Heathen Army,' a legendary Viking fighting force that once invaded England. Cat's team uncovers human stories from the front line, including evidence of women warriors and a lost king reunited with his son in death.

In 1986 a catastrophic blast, 400 times more potent than the Hiroshima bomb, blew the lid off Chernobyl's Reactor No. Four, igniting fires that burned for days and sending a radioactive cloud across Europe. Ill-equipped workers heroically sealed the smoldering reactor in a concrete sarcophagus, but the hastily constructed shelter was only built to last 30 years. Now, 30 countries have come together to pay for a 25,000-ton steel shelter which will...