Plot Synopsis

When 21-year-old Christina Whittaker disappeared in the small town of Hannibal, MO, a frantic search immediately ensued. Eight months later, filmmaker Christina Fontana met Whittaker's mother when filming a documentary about the families of missing persons. Little did Fontana know, this one case would lead her down a dark path full of conspiracies, betrayals, suicide and murder. Using more than 400 hours of footage from field investigations and video diaries filmed over 11 years, this documentary follows not only a complex search for a missing person, but the journey of a filmmaker who becomes dangerously ensnared by the story she's documenting. The first three episodes of RELENTLESS dropped on Monday, June 28, 2021 on discovery+. A new episode debuted each Monday on discovery+ through July 19. On Friday, July 2, 2021, Investigation Discovery aired a half-hour version of the first episode as a series sneak peek. RELENTLESS then had its linear television debut on Sunday, January 2, 2022 at 10pm ET/PT on Investigation Discovery.