Credits. Elements. Meth.
Back in the ol' present tense, Walt is cleaning the pizza off his roof, while Mike the Cleaner, still in his car down the street, updates Gus on just how oblivious Walt is to almost having been Tortuga'd himself. Interestingly, Mike confirms that "Saul Goodman does need to know," so whatever narcotic executive loop we've got here, Saul's not necessarily a part of it.
Meanwhile, Skyler drives home from work as a children's-music CD plays endlessly. She's singing along, but in that "kill me now" cadence of a parent who may never again know a moment where "Old MacDonald" isn't running a Mobius strip inside their head. Her mood changes from one of despair to overt anger when she spots Walt's car in the driveway. She pulls in and calls Walt ... who peeks out at her from behind the drapes as he answers. They proceed to have the same conversation they've had three times now, only this time it's while they glare at each other from less than 100 feet away. She tells him she thought they came to an understanding (i.e. stay away or I'm ratting you out). Walt basically tells her it's his house, and if she wants to talk about it, they can do it inside. Inside, it's clear that Walt's conversation with Saul last week about all that Skyler stands to lose by turning Walt in has made an impact. He's decided to call her bluff. Skyler, desperately clinging to the notion that Walt has no say in the matter, picks up the phone to call the police. He lets her. She dials the number and lets it ring. He encourages her. The dispatcher answers, and with Walt giving no ground, Skyler -- shaking -- says she would like to report a domestic ... issue. It's like counting to three in front of an insolent child. "Two and a half! Two and three-fifths!" No matter how small the fractions get, Walt is confident that he's got her. Which, honestly, must make the guy feel pretty satisfied, right? His massively illegal and destructive meth business has gotten him wedged into a position where his wife can't even divorce him for being a liar and a criminal because it will so thoroughly rip every corner of her family apart. High-five, Walt. He tries to paint it nobly, saying this family is everything to him, and that's why he's willing to let her go this far. Turn him in, even. Ten to one says Walt even believes this is the reason.