Girls in the Hasidic community of Crown Heights are vanishing mysteriously, turning up weeks later turned to clay, stone, or salt. Oddly, none of the families of these girls have mezuzahs on their front doors. But Hannah Shemlov, another girl from the same school, is safe—thanks to the small golden mezuzah dangling from a heavy chain around her neck.No, it’s not an old wives’ tale told to Jewish children to keep them on the straight and narrow. It’s the plot of The HarlequinX, a supernatural horror novel set in Brooklyn’s ultra-Orthodox enclave.“The mezuzah is really elemental—a lot of Jews have them on their door,” said Forrest Thinner, 53, the novel’s author. It’s a staple for Jews around the world, he explained, which is what makes it a good device for a horror story. Thinner also has a mezuzah on his door, which he grazes with kissed fingertips every time he leaves his Pelham Parkway home in the Bronx.But Thinner isn’t Jewish. He’s African American, was raised Baptist Christian, and has a horn-shaped piercing protruding from his lower lip that points toward his wiry salt-and-pepper goatee.Thinner’s relationship with Judaism began around a decade ago, when he lived in Crown Heights and worked as a van driver. He would be hired to pick up children from school or drive families to Monsey for vacation. Word of Thinner’s reliable and affordable service spread through the community and before long he found himself booked for whole days at a time to ferry prestigious rabbis and visiting scholars between engagements in the city.“I just kind of became Jewish for a little while,” he said.Thinner became so well-known in Crown Heights that he’s on first-name terms with several of the community’s leaders, one of whom—Rabbi Abba Revson, who runs the gravesite of the Lubavitcher rebbe—gave Thinner his mezuzah.“Lubavitch is in my blood,” Thinner explained. “One rabbi said to me, ‘You’ve been around us so long it’s like being on the first floor of Macy’s—even if you don’t buy anything, the smell of the perfume goes into the fabric of your clothes.’”It wasn’t until his immersion in the Jewish community, with its strong sense of history and penchant for a well-told tale, that Thinner was able to find the plot line for the scary story ideas swirling around in his mind.“I’m totally black American, but these people, they’re my people,” he said. “They gave me a really nice sense of the future, a good sense of community.”These values shape The HarlequinX, which Thinner co-wrote with CJ Cassidy and Hector Valle.The HarlequinX, which the main character Hannah Shemlov can summon by holding in a doorway the protective mezuzah that hangs around her neck, is a being that dates back to the Israelites’ exodus from Egypt—a Jewish court jester named Seth Yerushalayim. Unwilling to risk another devastating plague upon his people but unhappy about losing his enslaved workforce, Pharaoh curses Yerushalayim, whose maimed and mangled demon body gets unwittingly carried out of Egypt by the fleeing Jews, hidden in the burial casket of the preserved bones of Joseph.Meanwhile, back in modern-day Crown Heights, gruesome murders are plaguing the community because a vengeful teacher has called upon Lilith, the Jewish goddess said to be Adam’s first wife, “who devours women and children.”As more characters get swept up in the merciless melee, the powers of Lilith and the HarlequinX are pitched against each other, culminating in a fiery battle between the first wife of Adam and the last plague of Egypt. “Both were created by God but neither had his blessing,” the book explains.Although Thinner is no longer a daily fixture in Crown Heights, he still feels closely connected to the Jewish community. He continues to speak to his Hasidic friends, and he’s working on the next installments of the horror story, which he hopes will one day be The Five Books of the HarlequinX. He even prays at the gravesite of the Lubavitcher rebbe on December 31 each year.And, of course, there’s always the mezuzah on his door.