I REALLY enjoyed this story. I'm usually not a fan of the "Unknown Threat" scenario, where the argument is usually that the reader's/listener's/watcher's imagination will create something deadlier or more horrific than the author. My counter argument would be "then why don't I just write a story that I want to read myself ?" The reason to engage in someone else's work is to entertained and hopefully somewhat surprised. As fas as I'm concerned it's the author's job to tell me what's going on, to take me on a journey. After all, one doesn't buy an incomplete map or hire a guide who only knows bits and pieces of the way to your destination. Somehow, someway, however, this tale reaches a perfect balance between showing what the danger is and leaving the listener to fill in the details of the actual threat. We know it came out of the sky, someone described it as an act of God, it caused a power outage (either directly or indirectly) of an entire city which is being evacuated, it was dangerous enough for police and military to start shooting at it, and people started running, screaming, and jumping off the bridge when it (they?) got close. Aliens? Zombies? Demons? Kaiju? Any of these would fit here, and while I very much would like to find out what happens next, in this VERY rare case I'm fine not knowing. Kudos to the author for finding that sweet spot. Well done.