Walt ties up loose ends.

Hank finds out about Walt being involved with Mike leading to him piecing everything together about his involvement in the blue meth/Gus Fring operation.

Walt takes care of loose ends; Walt makes a dangerous decision

I read an article about the opening scene of the season where Cranston said he asked Gilligan to give him some hints about what was going on there so he would have some idea of how to play the scene. He said his family was "gone" and that he was back to "protect someone." Cranston said he asked if the cancer had returned and Gilligan would not say. Now that could just be what Cranston told the press to throw off expectations for when that scene is finally explained but I would guess the cancer does come back.

I can't imagine the "someone" he is returning to protect is anyone other than Jesse.

if by saying that his family is "gone" that they've been killed possibly or if they're just in hiding someplace from Walt. Possibly under witness protection or something maybe. I'd probably guess the latter but again you never know with this show what they've got in store.

uses the Ricin, probably on Skylar, or possibly on Marie. Gilligan previously said that Walt does something unforgivable, and this seems like the episode to do it.

I could definitely see something happening with the ricin. He very deliberately hid it instead of just getting rid of it. To me that seems to be telling that he's keeping it in case he may have to use it again. Using it on Skylar would make the line about his family being "gone" make some sense. I do wonder what she would do to set him over the edge though if that's the case..possibly say that she's going to tell Hank or Marie about what's going on with Walt?

the only unforgivable things I could see him doing is killing his son, he really is the only innocent person in the whole series

he convinced his dad to buy him a car. At least it wasn't breakfast though

I think Marie is innocent(other than some shoplifting :lol:) and Walt didn't hesitate to use the fear of her death in the past(at the scrapyard) to manipulate Hank. And while Skylar is not innocent, murdering the mother of your 2 children in order to preserve your drug empire is imo, unforgivable. One of the issues complicating the potential death of his kids, presumably accidentally, is that none of them are living at home at the moment.

I don't think he will try to kill Jesse, Saul or Hank(at least not until next year!)

Also, according to the sneak preview, there are 10 people on the 'list' not 9--the lawyer who made the payoffs is included as well.

Really though that would't even make sense. Walt has no motivation for killing Walt Jr. that I can even remotely think of. I don't think he's quite that far detached that he's willing to kill his own son. I could more see Skyler simply for the fact that he feels she's keeping him from being with his children and she poses the threat of spilling the beans to somebody. Not to mention the fact that he knows she wants him dead. Killing Skyler in my mind though is pretty unforgivable because granted while she hasn't been innocent throughout the series she's more or less been a victim of his decision to cook meth and break bad. She hasn't really done anything that justifies her being killed in my opinion at least.