For the next few days, Tess, Jaime, and Theo assembled names for their list of possible owners of the Jennings dress. Tess was as eager to figure out the mystery of the black gown as she’d been every other aspect of the Old York Cipher, and her mind churned with questions. Whose gown could it be? Did it belong to Eliza Hamilton (who mourned her husband for fifty years)? Or to someone like Anna Ottendorfer (a widow-turned-owner of a mid-nineteenth-century German-language newspaper in New York)? Or maybe it belonged to the elusive Ava Oneal (a puzzle of a whole different kind)?

But as eager as Tess was during the day, her nights were different. Ever since she began reading about the people of New York whose lives were wrapped up in the mystery of the Morningstarrs, Tess’s sleep—when she could actually sleep—was fitful and filled with monsters.

Sometimes the monsters took recognizable shapes. Tess floated alone in a vast ocean, the water cold and inky, as a fin raced toward her. Tess careened down a city street, as a Komodo dragon the size of a truck sprinted behind. Tess tiptoed around the hallways of 354 W. 73rd Street, Mr. Stoop and Mr. Pinscher lurking around every corner. Tess was strapped to a chair while Darnell Slant ranted about progress from a TV and the walls of her home collapsed around her.

And sometimes there were no monsters in her dreams, and that was worse. She dreamed it was 1851 and she was waiting with Elizabeth Blackwell, the first woman doctor in America. Dr. Blackwell had put out a sign at her office in Manhattan, advertising her services as a physician, but even women were too angry and afraid to see a woman doctor. In the dream, Tess kept asking what was wrong with a girl being a doctor? Why was everyone so angry? What was everyone so afraid of? But no one had any answers.

And then it was 1793, before the time of the Morningstarrs, and she was sitting with black and white and brown orphans in the home of Catherine “Katy” Ferguson, who had invited the orphans inside for lessons in life and scripture. The daughter of an enslaved woman, Katy herself never learned to read or write, but she remembered what her mother had taught her about the Bible when she was little and wanted to pass on this knowledge. Tess asked her who had stolen her mother from her homeland, who had enslaved her, who had kept Katy from learning to read, who was keeping her from her mother in Virginia, but Katy kept shaking her head. There was no single monster, Katy said. Or too many monsters to count, which amounted to the same thing.