I'm gonna have to go with sewer backup

OK, so my toilet wasn't flushing to great (glugging noises) and my shower wouldn't drain.

(My shower often needs a shot of Liquid Plummer.  My luscious locks tend to find their way into the drain.  But the toilet simultaneously?  That doesn't seem right.)

But, I used a plunger on the toilet and a bottle of Liquid Plummer, followed by a bottle of Drano, in the shower.  So far so good.

Of course, there was also that small puddle of water on the floor under the litter box in the tiny bathroom.  And when I lifted the lid, the toilet in there looked like it had some brown water within, which was odd, as the only one who uses that bathroom is the cat, and she hasn't mastered the toilet (and certainly hasn't learned to put the lid back down).

So, I suspected sewer backup, but it still seemed a bit odd, as water seeks its own level and the toilet bowl is definitely not the lowest water in my house.

Today, I happened to take a peek in the guest bathroom.  Where the tub has, er, dried brown gunk all around the drain.

Yeah.  There's only so far denial can go.  Just bought me some sewer-line root-cleaner.