So we have had multiple carpenters/staircase experts/contractors come in and give their opinion... The most recent staircase expert (only does stairs) came in and recommended tearing it down and building a new staircase... 2 hours later I had a flooring expert come in and pretty much skip the flooring but marvel at the staircase for 20 minutes and saying over and over again, "you have to save this." I think it's nice, but not that nice =D... Anyway, right now we are planning on going with a carpenter who thinks he can jack up themiddling/floating/sagging part, put up a new stringer and use some big old lag bolts to secure it. He said it may cause some cracks in the ceiling/walls eventually but that is only cosmetic. Anyway, I welcome any and all opinions/advice/thoughts/anything! Thank you so much. The Good: The bad: (picture does not do the sag justice but you can see the window frame is close to level) "Look, Ma, no stringer!" Thank you so much for any and all advice/ideas/opinion/anything!