We skipped church, went only to Sunday School. That may have been a good idea...I assist with the Pre-K and K class. When I got to the church, I found no teacher for my class...or the 1st and 2nd grade class...or the 3rd - 5th class.
There were already 13 kids...and I ended up with nearly 30. I had no lesson plans, no papers for everyone to do, nothing.

One of the helpers with the older kids came over to assist, thankfully, since several of the youngest kids can't go to the bathroom alone yet...and we just watched movies for most of the hour.
Then I turned them loose to look at library books or whatever...ended up with most of them in the Pre-K and K room, playing with Play-Dough, construction papers, markers and the chalkboard.
I think I'm going to make up some sort of generic lesson for all age groups, and have it ready for the next time this happens.