I have a 1/2 formed Breaking Bad theory….
Walt’s family is killed, maybe even in his own house (hence the fence up around the house). Walt’s presumed dead. But he somehow escapes. (perhaps he’s not home when it happens and goes on the run) After Walt’s family is killed, Hank finally is able to go public with the information about Walt being Heisenberg. The community is shocked. (Hence his neighbor reacting the way she does)
After hiding out for awhile he realizes that even though he’s alive he’s nothing without his family. Walt decides to get revenge. He makes a plan. He’s going to kill the men and women responsible for murdering his family. But Walt isn’t going to go to jail. So he returns home to get the ricin. Because after he goes all Scarface with that giant gun. He’s going off himself.
What about Jesse? I have no idea. I don’t think Walt’s going to kill Jessie but I think that Jessie is going to kill himself.
Interesting theory, but I’m more in the camp that Hank will harm their family somehow… It’s been his MO the entire series… He’s too passionate/dualistic.