Chris Nicola did an astonishing thing. The New Yorker and amateur spelunker went to Ukraine soon after the Soviet Union collapsed, looking to explore both his Eastern Orthodox heritage and the gypsum caves of the region. He found an incredible story of Jewish heritage that involved the caves whose interiors rarely had been seen by human eyes.

Underground, he stumbled over the remains of stoves and furniture and, finally, a woman’s shoe. He couldn’t imagine why a woman would have been that far below ground, so he went digging in the towns above. At first, no one would talk — the citizens of the newly independent country weren’t yet prepared to speak to Westerners. But, as Nicola says, “I’m very outgoing,” and he kept trying for years, when he finally heard: “Maybe some Jews lived in the cave.”