Back at Jesse's, Mike is advocating eschewing the methylamine and opting for a pseudo-cook for a few months. Walt says it'll cut down their output by 25 percent and they'll have to eat $80,000 on all their equipment that's no good for a pseudo-cook; they'd be in for a fraction of the profit. Mike argues that "Making less money is better than making no money," which cheeses Walt off. Walt says that's the case for Mike only because he has these golden parachutes to pay out to his incarcerated nine.
They resume the same old argument, as the camera pushes in on them in the foreground, Jesse on the couch behind them, once again the child-of-divorce angle being strongly pushed. And in an almost exact repeat of the season premiere (lots of echoing in this episode), Jesse comes up with an idea so that Dads will stop fighting: what if they can rob the train without anyone realizing anything has been robbed?? Walt and Mike turn to him, all "...Magnets, you say?"
After the break, they're out in the desert, walking the tracks, measuring the distance from a road crossing to an overpass bridge; Jesse declares it's perfect. Cut to the Vamonos crew helping them dig two holes in the ground below the overpass while Mike plays the part of the grumpy lookout. After the holes are dug, two plastic barrels are placed in the ground and buried but for the holes at the top; then a tanker of water (wherever they got THAT) pulls up and they fill up the one jug with water.
Confused? Allow Landry from Friday Night Lights (whose name is still officially Todd, but I'm going with Landry) to act as your surrogate. He asks Walt to explain it to him, and Walt magnanimously allows Jesse to expound upon his own plan: "It's all about the weight, yo." They're going to steal 1,000 gallons of methylamine and replace it with water so that when the train gets weighed again in Texas, no one will know anything's been stolen. Jesse takes a moment to be super foreshadowy, impressing upon Landry the seriousness of boosting methylamine in a post-9/11 age: no one, absolutely no one, can know they did this.