Not really buying the proposal. Particularly because I haven't bought into the Mags/Kate relationship at all thus far. They've shared, what, one tender moment in 18 issues? They've had, what, two dates ever? Kate kept saying how she missed Maggie, but how could she when they've barely spent any time together? I'm really hoping that this is just an impulsive move by Kate and it ends poorly. Not poorly as in Maggie dies or something, but a move like this has the potential to just totally ruin a relationship. Like, "Hey, I've been lying to you all this time. Oh yeah, will you marry me?" I can see Maggie saying no and its being the start to an enmity between them. I think it would be great if it were revealed that Kate were much more into the relationship than Maggie, possibly because she has alienated the two people closest to her lately (Jake and Bette) and is looking for a substitute of sorts. That would explain a lot of what's happened in this book so far as regards the relationship, but I'm not terribly optimistic about it.
About the Bones reveal, I do think they are familial, but probably half-siblings. It would explain why the DEO has taken such an interest in Kate. And I don't know why you guys are saying he's black - he's always had invisible skin and organs, so I would assume that would exempt him from the standard racial categories.
As far as how the story ended - a little bit rushed, I thought. WW and Kate just bump fists then go their separate ways? Pretty underwhelming. And Bette's new name and costume are just awful.
Kate's crushing the surveillance device was pretty predictable and disappointing. Typical superheroes who don't trust government agencies. I get that she was blackmailed into working for them, but she certainly has taken great advantage of their technology during this arc, so I would hope that, contrary to most "superhero-works-for-the-government" narratives, she eventually sees the value in working for them and begins to believe in their cause rather than grow disillusioned because she had to do things she found reprehensible. That would be different.
Still, though, this is a good book. The layouts and art are awesome and even though I don't like McCarthy nearly as much, I've always been a big fan of Bones, Chase, and the DEO and there are a ton of loose ends there, so let's see what happens.