Just off the coast of Alexandria, 23 feet below the surface of the Mediterranean, lay the remnants of a mysterious ancient monument. For more than 30 years, the French explorer Franck Goddio has been working under a shroud of secrecy, hoping to confirm these remains as the temple of Cleopatra. If true, this unprecedented discovery could reveal vital new information about Cleopatra's reign and her connection with the goddess Isis.

"Chasing the Plague" looks at the societal impacts of the bubonic plague on medieval Europe as scientists today track down the earliest known bubonic plague victims. They are studying the virus in hopes of preventing future outbreaks. What happens when a third of a continent's population is wiped out?