While mapping out the largest cave system in Ukraine, explorer and investigator Chris Nicola discovers evidence that five Jewish families spent nearly a year and a half in the pitch-black caves to escape the Nazis. This is the story of the longest uninterrupted underground survival in recorded human history.

This extraordinary testament to survival from Emmy-winning producer/director Janet Tobias brings to light a story that remained untold for decades: that of thirty-eight Ukrainian Jews who survived World War II by living in caves for eighteen months.