My guess is that Kim does something that pushes him over the edge, maybe she's the reason he knows about vacuum repair in the first place.
I still feel like this, too. The last 2 episodes, while both good, have mostly seemed like table setters and I'm really looking forward to D-Day, but I feel like we have a long way to go between where Jimmy is now and Saul calling Francesa "honey tits" and laughing about it (though I guess him pointing out how much she's getting paid when he was being a bit of a dick to her about the phone call can kind of explain why she would put up with it).Great 2 episodes. I'm still a little worried that they're going to have to rush through some things to get to the end of this show and have Saul be who he is once Breaking Bad starts, but this show has earned the benefit of the doubt that they know what they're doing.
I'm still going with my vacuum repair idea, but now it has something to do with Kim figuring out it was Gus she was talking to on the phone, Gus telling Mike to have Kim killed and him and Jimmy using her disappearing as a way to fake her death.My guess is that Kim does something that pushes him over the edge, maybe she's the reason he knows about vacuum repair in the first place.