Spoilers for Episodes 22/23
There are a few more spoilers for the final 2 episodes popping up. Here's the one I think has the most.
http://tvline.com/gallery/may-sweeps-spoilers-2017-finale-episodes-photos/#!24/sweeps-supernatural
As the British Men of Letters start to make their move, “people that Sam and Dean know/love pay the price,” forcing the brothers to take “a much stronger role in the wider hunter community” as generals, executive producer Andrew Dabb previews. Mary also faces a difficult battle with the Brits: She, “more than Sam and Dean, is on the inside, so her journey out may be a little bit more complicated,” Dabb notes. Meanwhile, Cas’ return brings “a lot of clarity” about “why he’s been in Heaven for so long” and “his own point of view on why he went.” And as the impending birth of Lucifer’s Nephilim offspring nears, “everyone is going to activate more and more.” Also on tap: the returns of Jody Mills and her surrogate daughter Alex, and “two surprise appearances, one by a relative newcomer and one by an old favorite.”
SEASON FINALE (MAY 18): The two-hour finale – the first episode deals with the Brits, while the second is Lucifer-centric – is “big and, I hope, somewhat bold and, in some ways, heartbreaking,” Dabb shares. The closer “also opens up some new stories for Season 13 in a very interesting way.”