So, being an inquisitive guy, I downloaded the Solus .iso. Burned it, booted it, said, "that's interesting, and rebooted. The Solus live session came back up with no USB installed. I rebooted again and again, and it kept coming up. Shutting down didn't fix it.

I finally shut down and removed the RAM sticks, and let them rest for a few minutes. I was then able to boot.

Then, I saw that my external HD had been named "Solus," and had been formatted.

Fortunately, I had a backup.

But, be vewy, vewy careful when hunting Solus wabbits.