A horse? At this hour?

[forgotten_aria]

At 5am or so, I heard this noise. I swear is sounded like a horse at full canter. It got louder and I saw something pass the windows, but not what. It looked to be too slow for a horse, too smooth. I doubt it was a horse, but I'm really confused by what I heard. Anyone know what it might have been?

This is on my street, so I doubt it was some Paul revere reanactment or anything.