A handwritten sign appeared in the elevator Monday saying, WHOEVER KEEPS WALKING THE BROWN DOG AT MIDNIGHT, PLEASE TEXT ME. I assumed somebody wanted to complain about barking. By Wednesday, three more residents had added their numbers. The dog belongs to an elderly man on the fourth floor who recently had knee surgery, and different neighbors had quietly been taking turns walking her without coordinating. The sign was from a woman trying to create a schedule. They now have a group chat called Linda’s Staff. I joined after covering Friday night. Linda is the dog. Her owner isn’t in the chat because everyone agrees he would try to pay us. Linda is the only resident in the building with seven personal assistants and no rent.