“I’d forgotten all about that silly little secret compartment,” Swann finally said, wiping his eyes, after she’d finished telling him everything she’d discovered so far. “You have the map with you now?”
“Ramona Wu and your father, and mother, were old friends?” “And a couple others, all from their university days. There were seven of them in total,” Nell answered. “I couldn’t believe it either.”
“What was he going to do with this stupid map, if not sell it? Why did he keep it all this time, then?”
Her mom had the map and was killed when the cartographers burned their house down. Her dad told her it was junk when she found it to keep her from getting involved.
So Nell could go to Romi's shop because the map was drawn on the business car, and if she had the Sanborn map in the NYPL she would have probably found the closet on that map.
He wondered how William got into the building unseen by the rest of his thousands of employees, on the days that he was here. Maybe he had his own secret entrance and elevator. Or maybe he just lived here, and never left, like a true ghost.