Angela’s friends couldn't understand what had happened to the healthy, active, 43-year-old… Her story tonight at 10/9c on an all-new Dateline. | Dateline NBC

A medical mystery was about to turn into a full-on police investigation… Tonight on an all-new Dateline at 10/9c on NBC. | Dateline NBC

You’re witnessing something highly unusual… Watch the full story tonight at 9/8c on a classic 2-hour Dateline. | Dateline NBC

Cheryl had a nagging feeling… Where was her daughter, Kelsey? The full story tonight at 9/8c on a classic Dateline. | Dateline NBC