Three important plot developments happen in this week's reading (things are finally converging a little!):

Lenz starts killing animals as an outlet for the rage and powerlessness he feels that commonly beset drug addicts in their first few months of abstinence. On one of his trips, he kills a bunch of big burly Canadians' (insurgents?) dog, they come to Ennet House for revenge, and they get fucked up by Gately, who gets shot in the fight
Pemulis finds out Mrs. Inc is Xing John Wayne in her office
Orin finally actually meets and speaks with someone from the A.F.R.

Plot development one takes up most of this week's reading (Lenz, Green, and Gately), but I really don't like Lenz and I find reading about him exhausting, so I'm going to devote most of this post to Mario. From page 589-593, Mario goes on a walk late at night to Ennet House, hears a recording of Madame Psychosis's show, and chews on a core theme of the book from his very unique perspective. On his walk, Mario thinks about Hal, and it's wonderfully wholesome how much Mario loves Hal:

"Hal had asked him when he’ll start coming back to their room to sleep, which made Mario feel good."
"Mario loves Hal so much it makes his heart beat hard." followed a page or two later by "when he thinks of Hal his heart beats and his forehead’s thick skin becomes wrinkled."

This is especially interesting because all the Hal Mario interactions so far have made Mario seem like a child: Hal unwittingly saving Mario from Millicent Kent, Mario keeping Hal up asking him questions about Himself and Moms, and Hal threatening the people from UHID when they come to recruit Mario, but actually Mario might be the only person who really knows what's going on in the book (with the possible exception of Lyle, who I think we can safely discount because he dispenses advice in a high school gym in exchange for sweat, his primary form of sustenance).

Mario’d fallen in love with the first Madame Psychosis programs because he felt like he was listening to someone sad read out loud from yellow letters she’d taken out of a shoebox on a rainy P.M., stuff about heartbreak and people you loved dying and U.S. woe, stuff that was real. It is increasingly hard to find valid art that is about stuff that is real in this way. The older Mario gets, the more confused he gets about the fact that everyone at E.T.A. over the age of about Kent Blott finds stuff that’s really real uncomfortable and they get embarrassed. It’s like there’s some rule that real stuff can only get mentioned if everybody rolls their eyes or laughs in a way that isn’t happy.
...
what was unpleasant was that Mario was the only one at the big table whose laugh was a happy laugh; everybody else sort of looked down like they were laughing at somebody with a disability. The whole issue was far above Mario’s head, and he was unable to understand Lyle’s replies when he tried to bring the confusion up. And Hal was for once no help, because Hal seemed even more uncomfortable and embarrassed than the fellows at lunch, and when Mario brought up real stuff Hal called him Booboo and acted like he’d wet himself and Hal was going to be very patient about helping him change.

Mario is severely physically disabled (this passage opens with Mario getting severely burned by a stove because he can't feel pain), but almost everyone in the book hurts more than he does because they don't understand a core theme of IJ- that there is very little more important than honestly and respectfully engaging with what is real.

Some other things I found interesting:

John Wayne is wearing nothing but football pads and a football helmet, and Mrs. Inc is wearing a cheerleader's outfit. Is this a gross Orin and JvD reference? ¯\_(ツ)_/¯ we shall see
The DFW penchant for wrapping important information or horrifying backstories in unremarkable if a little weird situations should be pretty obvious by now. Annulation and its disastrous environmental side effects is the primary scientific cause of the Great Concavity, a key part of the plot, and it is explained in a conversation between Pemulis and a blindfolded Idris in a sly attempt to acquire Idris's urine for Pemulis's upcoming urine test for his role in the Eschaton debacle.
On page 549, "The Berkeley cartridge had vanished from an S.F.P.D. Evidence Room an electron-microscopy toss of which had revealed flannel fibers." Marathe covers his legs with a flannel blanket, and in the Antitoi brother's chapter every A.F.R. member also had a flannel blanket.
On page 560, "Or like e.g. of a suicidal Nuck cult of Nucks that worshipped a form of Russian Roulette that involved jumping in front of trains and seeing which Nuck could come the closest to the train’s front without getting demapped."
Mario's passage also highlights something very wrong with Hal:
He can’t tell if Hal is sad. He is having a harder and harder time reading Hal’s states of mind or whether he’s in good spirits. This worries him. He used to be able to sort of preverbally know in his stomach generally where Hal was and what he was doing, even if Hal was far away and playing or if Mario was away, and now he can’t anymore. Feel it. This worries him and feels like when you’ve lost something important in a dream and you can’t even remember what it was but it’s important. Mario loves Hal so much it makes his heart beat hard. He doesn’t have to wonder if the difference now is him or his brother because Mario never changes.

Pay attention to the small, seemingly irrelevant details from now on, because most of them are important, and it's so satisfying when you catch one of his self references later on.