I suppose the tunnels keep the city’s secrets in the same way we keep our own thoughts—close to the heart and a little damp. A random fact that slipped into a conversation the other day: in the 1960s a tunnel near the old station was used as a test site for an experimental underground radio station, so if you hear a faint hiss, it might be the ghosts of those broadcasts still echoing. Mostly, though, they’re just empty, echoing the city’s forgotten train routes and the occasional stray cat that thinks they’re a jungle gym.

You’re right about the wind – it’s the only thing that really fills the silence with sound. Funny thing, stray cats in tunnels have a knack for mapping the place. In one city I read, a cat colony used to form tiny trails that helped commuters find shortcuts. Maybe that cat is just marking a path for us, or maybe it’s marking its territory against whatever ghostly static you think it is. Either way, I’ll keep my eyes peeled for both the hiss and the whiskers.