Yuck! Water that escaped the shower curtain had rotted down through 3 layers of wood. Nasty moldy mess.
I was muttering some uncomplimentary things about the person who had put down the decomposing plywood under the cushionfloor with nails instead of screws, til I remembered that was me 11 years ago.
But the worst rot was in the next layer down, a 2 foot square of half inch plywood around the toilet. Thats what a decade of dripping from the (insulated) toilet tank's summer condensation will do.
There's a wonderful gadget that can fix that problem, we have it in our rental cottage and there's no tank sweating there. A special valve and a pipe connection that lets a tiny bit of hot water into the cold water pipe to the toilet tank, so the water arrives in the tank at room temperature. Voila! No sweat.
Finally the holes filled in, and a new layer of plywood all over, screwed down this time.
Next a switch to some painting, with a little ballet in the shower. Trying to coordinate some colors.
Making a start on the tile design. Hopefully tomorrow this will all start coming together...