Walter, Jesse, and Mike face a methylamine supply crisis when a GPS tracker is discovered on their shipment barrels. Mike wants to kill supplier Lydia, believing she planted it, but she proposes an alternative: robbing a freight train carrying 24,000 gallons of methylamine through remote New Mexico territory. Meanwhile, Skyler negotiates with Walter to keep their children permanently with Hank and Marie in exchange for her continued cooperation with money laundering.

The episode explores the moral compromises each character makes to achieve their goals. Jesse designs an elaborate heist to steal methylamine without killing the train crew, directly opposing Walter and Mike's willingness to murder witnesses. The successful train robbery seems to vindicate Jesse's ethical approach until new crew member Todd spontaneously shoots a child witness, ...