In 2013, Edward Snowden was an IT systems expert working under contract for the National Security Agency when he traveled to Hong Kong to provide three journalists with thousands of top-secret documents about U.S. intelligence agencies' surveillance of American citizens.
More than 70,000 Americans died from drug overdoses last year, and a growing number of those deaths are attributed to the powerful synthetic opioid fentanyl. Journalist Ben Westhoff says the drug, while an important painkiller and anesthesia medicine in hospitals, is now killing more Americans annually as a street drug than any other in U.S. history.
Underwater explorer and photographer Jill Heinerth has dived into unmapped caves deep in the earth, and beneath a giant iceberg. She's seen hidden creatures old as dinosaurs, and witnessed scenes of surreal beauty. Her work is so dangerous, over a hundred of her friends and colleagues have died in caves. She talks about the risks and rewards of her work.