Natalie's at a Japanese restaurant with Michael and Sam (who's embarrassed about taking off his shoes with a hole in his sock) and hands over a dossier on "Novichok Agent," which Sam recognizes as bad juju. She asks them to brainstorm, and Michael suggests a plan of faking a gas leak to convince the bad guys to move it out so they can take it while it's on the move. Natalie's end of the deal is to stay where they can see her and give Fi's gun back before she leaves. Natalie agrees, and they toast with some sake. Just a happy murderer and her happy accessories after the fact.
Michael VOs what everyone knows about natural gas smell: it's actually odorless, the notorious smell being an additive. Fortunately, Fi has a big fat jar of that very stuff, as well as a pump and a hose and, for some reason, a stroller. Oddly, however, she's setting it up at Madeline's house, which means she has to have an awkward conversation with her which touches on kids (short answer: NONONONONO) before Madeline brings up the subject of Michael and Jesse: she wants Fi's help with her plot to stick them in a room together. That should go well.
While Michael VOs about the strain that blackmail can put on a relationship, Marv meets Sam at a marina. Sam points behind Marv, who turns to see Jesse and is pretty pissed off about it, this being the second time Jesse's pulled this. Jesse informs Marv that he helped take down Drake Technologies, and Marv is impressed enough to keep listening. Jesse hands over the e-mails pointing to the auction, and Marv agrees to look into it. After Marv leaves, Jesse admits to Sam that he feels like shit for playing a friend like that. "Yep, I know how you feel," Sam says brightly. "But you know what always cheers me up? Stealing a chemical weapon from a bunch of crazy South Americans." Funny, that always fills me with malaise.
While staking out Marco's place again, Michael and Jesse now have to contend with a bored Natalie. Fi pulls up out front in her car, and the three watchers argue a bit while Fi starts wheeling that stroller out along the street and up to a gas valve. Meanwhile, Sam is posing as a gas company guy ordering an evacuation. When the smell hits, the goons are ready to move, but no sooner have they opened up a vault in the shed than Marco comes and shuts it again. Per Michael's VO, he apparently fears something even more than getting blowed up. Sam is driven off without ever being allowed through the gate, and worse yet, one of Marco's goons flags down Fi as she's trying to leave. Michael and Jesse are about to go in, but Natalie wants to be the one to save the day. "You don't like what you see, then you can shoot me first." They should probably do that anyway. Meanwhile, the goon is wondering why Fi has a stroller with no baby, and he shows her his gun to alert her of his suspicions. Fi is busy stalling when Natalie runs up pretending to be the lady Fi stole the stroller from. Fi plays along, and... catfight! Good enough for the goon, who tells them both to get out of there. Plus Fi got to pop Natalie in the face, which she's probably been wanting to do for like a year and a half now.