Alone with Skyler, Walt says this phase will pass, but Skyler tells him not to bother to talk to her like they're on the road to reconciliation. She's not ever changing her mind about him. He refuses to accept that; she's his wife, after all. "I'm not your wife," she snaps back, "I'm your hostage." She lights up and offers Walt a deal: she'll launder money, she'll keep secrets, but the kids stay at Hank and Marie's. Walt insists the kids are not in danger, but Skyler, ever the skilled debater, brings up Walt's own words from last week, when he tried to prove to her that people come around on him; remember when he bragged about someone holding a gun to his head? "There's nothing you can say that'll convince me there won't come a day when someone will knock at the door looking to harm you or me or all of us. And when that day comes, the children cannot be here." This at least shuts him up. "You agree to that, and I'll be whatever kind of partner you want me to be." Walt assents with his silence. "By the way," he snits, "you're visiting a therapist from Rio Rancho. Peter. Last name is up to you." As he leaves the room, Skyler looks at his dirty clothes and sniffs, "Out burying bodies?" Walt sneers back at her: "Robbing a train." [Note: Could you imagine if Skyler knew about that time the evil twin cousins sat on her bed with a huge shiny axe?]
Lydia sits in her office, late at night, and true to her word, she gets the manifest and contacts Mike. Later that morning, everything looks to be set. We can hear a train whistle in the distance. A truck drives up and parks itself across the tracks. The driver, the stooge in Saul's employ played by Bill Burr, gets out and makes like his vehicle is disabled.
Now, just to have this on the record, I have no idea how the team determined that the train would stop with the exact right car on the overpass bridge, especially since they didn't know where the tanker was on the train until six hours ago, nor the lengths of all the other cars; let's just chalk this one up to Walt's juicy chemistry club brain and Jesse's entrepreneurial spirit and move on from there.
Train approaches, train arrives, train crosses bridge, train stops exactly where they need it to. Once the train finally halts, Walt sends his boys into action; everything moves very fast: pumps are assembled, hoses unfurled, barrels uncovered. Bill Burr farts around with the conductors, trying to avoid arousing their suspicions by basically acting like the folksiest jerkoff you've ever seen; he gets them to check out the engine for him, and when they're sufficiently occupied, Walt sends Jesse and Landry up the embankment to the train. Jesse takes the below-tank action of siphoning the methylamine, while Landry heads to the top of the tank to set up the water replacement, with Mike keeping a watchful eye from the lookout post. The music is all tense and Jesse and Landry are working very hard unscrewing these giant bolts with giant wrenches and such; but everything seems to be going well.