Horror movies don’t usually disturb Flora Collins. But after she watched Jordan Peele’s Us—the 2019 thriller in which all humans have doubles living underground, waiting to escape and slaughter their aboveground twin—she left the theater feeling “discombobulated.”

A few hours later, on the street in Manhattan, a woman approached her claiming they knew each other. Collins was sure she had never seen this woman’s face before, but the woman insisted. “I felt like I was in an alternate dimension or something,” Collins tells me from her apartment in Brooklyn Heights. She later discovered that the woman was the mother of a former pre-school classmate—someone she hadn’t seen in 25 years, since she was three years old.