Somebody in the neighborhood has obviously been working on getting their bike up and running for the season.
It's blasted around the block a couple times now and is currently idling a few houses down across the street. It's not a V-twin, nor a boxer twin, either. It's a fairly big four-cylinder, I think, although it could be an inline triple.
When the temperature and humidity are like this and it's pitch-black night outside, and I hear that noise, I will be forever cast back to that Georgia night sitting astride the GPz550 we just bump-started, blue high-beam and green neutral indicators glowing up at my helmet...
"Do I know how to ride this? Of course I do!"
Of course I didn't.
But that just made it all that much more fun.