So, after a few days with a naked tree in the living room, we finally got the lights on last night.
Then, when I got home today,
the tree looked like this-------->
Notice the dark mid-section.
Well, we found where a cat had chewed through a cord (which they have NEVER done before), so Bryce stripped it and reattached it, and now we're back to normal. But, we'll have to be sure we're always close by when the tree is lit!