Dog Takes The Subway Every Day, Cop Turns Pale After Following Him

Amir was waiting at the subway, blending with the usual morning rush like any other day. Amidst the crowd, his attention was drawn to an unusual sight—a dog amidst the commuters. Initially, Amir assumed the dog was with someone, but he soon realized his mistake. The dog seemed alone, navigating the subway with the ease of an experienced traveler. Why was this dog here, and where was it heading?