So the past few days I've been trying to get the last two modules out, but it's just so fucking boring that I fall asleep trying to do it. Yeah, that's right - high level planar travel and interacting with the various Demon Lords is FUCKING BORING. I can, however, summarize because it involves the least amount of looking at the goddamned text and mathing out the various bullshit that happens.
First off, we have Enemies of My Enemy written by Wolfgang Baur.
So last time, the River Styx was flooding the planar prison, and Charon was riding his boat down it towards the PCs. He gives the PCs a lift out to Iggwilv's Landing, which has the MOTHER FUCKING SEA WYVERN docked at it because we can't just let this bullshit fucking ship go, ever. There's a sidebar about the PCs attacking Charon, because the boatman of the River Styx is "obviously evil". Apparently Charon reforms every 24 hours and continues trying to kill the PCs if they kill him, until he fucking kills them and then railroads them to the next part. No, I'm not fucking kidding. This is for a group of level 19 characters, and they get hit with the fucking railroad.
Why yes, someone at Paizo rubbed their 'Can't-MC-To-Save-My-Life' schlong all over this adventure path.
Anyways, the Sea Wyvern kind of serves a point, as it's permitted to ply the River Styx, which as alluded to earlier, touches a lot of layers of the Abyss. Great. First up is greeting Iggwilv, after fighting through her friends who want you to stop getting to her.
Iggwilv is, in fact, a female human wizard 26/archmage 4. Yeah. 30th level Wizard. Who has some Epic spells. Who could end this herself. She doesn't because ???.
Anyways, she gives the names of some of the others willing to help you oppose Demogorgon; Charon, Orcus, Gwynharwyf, Malcanthet (who has already fucked the PCs over a couple of times behind the scenes), Obox-ob, and Bagromar (one of Demogorgon's own lieutenants).
So the PCs go off to recruit Orcus in Thanatos, armed with a letter of fucking introduction written by Iggwilv. Thanatos has thin air that forces DC 18 Fort saves every hour or become fatigued, then exhausted, and you don't care because your party has Necklaces of Adaptation because they cost literally nothing and are the answer to 75% of all bad MC plans. Orcus requires a DC 50 Diplomacy check (with the letter of introduction somehow providing a +10) who then challenges them to a Trial of Honor combat by choosing their own champion to go up against Orcus' champion(s) - depending on if they make the check or not. If the check succeeds Orcus' champion is one CR 18 Female fiendish death giant. Otherwise they face two and a CR 20 crawling head.
They're transported into an arena to do battle - one PC vs one or three things. And I found the reason why this is so awful.

Wolfgang Baur is quite obviously a 1E or even 2E GM who likes to rub his Fuck You Dick all over everything he writes. Though Robert Lazzaretti is the cartographer I have no doubt Wolfgang is responsible for the "one inch = 100ft" thing.
Anyways, surviving the encounter enlists Orcus' aid, where he will drive an army to the Gaping Maw to fight Demogorgon. Also it provides us Orcus's stats, which is just a reprint from Fiendish Codex.
Then the PCs travel to the Court of Stars where at long fucking last the affiliation scores come into play; anyone with an affiliation score of 21+ in the Church of Whirling Fury gets to bypass the holy fuck annoying Tulani eladrin who tries to goad the PCs into attacking them so they can kill them, especially insulting any Evil characters or Lawful characters or, everyone if they took th efucking Sea Wyvern and rode across the Styx to get here. And if that doesn't work he subjects them to challenges for each PC in turn, challenges that include wrestling (winner is the one who pins the other for 3 rounds), jousting (the rules are fucking horrible, but I'll post them in a spoiler for people who want jousting in their games), or a steeplechase. All PCs have to succeed at their chosen challenge or the dickhole orders them to leave - it basically says "when you judge the PCs have had enough of this guy, end it".
Jousting!
Either way, Andros gets chastised by another dick-waving NPC (or he's dead), a ghaele bard 5/lyric thaumaturge 7 named Celeste, who takes them to Queen Morwel, Eladrin Queen, blah blah blah, who eventually tells them to go kill the linnorm Redfang who is poisoning Yggdrasil or ate a star from the Court of Stars or something, so they get sent to Yggdrasil. Redfang is an elite dread linnorm that is somehow CR 22.
Success gets them an audience with Gwynharwyf, who readily agrees to take her armies to the Gaping Maw.
Then the PCs go to Shendilavri to recruit Malcanthet to their cause, where they get to engage in a Diplomacy-off with the Queen of Succubi, and winning means someone gets to have 4 negative levels inflicted and get a +4 profane bonus to an ability score and all saving throws, in exchange for being marked by Malcanthet and lets them have a status spell that Malcanthet can always monitor as well as have Malcanthet always capable of communicating with them telepathically, while also letting Malcanthet use her SLAs through the character as if they were the originator of the effect. Also she can scry them.
Then she wants them to go capture someone named Crimson to get the Iron Flask of Tuerney which can be used against Demogorgon.
Crimson is a Succubus assassin who's pouting that Malcanthet was letting an incubus named Sypharian take the important killings. They have to fight their way through six vampires and then talk to Crimson. They can lie to her ,make a DC 50 Diplomacy check or win an Intimidate check to make her go back to Malcanthet, or physically restrain her and carry her back. Crimson is a lilitu bard 12. So taking her back or bringing her back means she gets executed by the rest of the order she belongs to.
You know, I get what they're doing here - success at a price. Could they have been a little more fucking SUBTLE with it? Maybe in a way that would let the fucking Paladins play, too?
Anyways, on Crimson's death Malcanthet gives them the Iron Flask of Tuerney, which lets them capture Obox-ob to unleash against Demogorgon. Guess where the PCs go next.
But first, I want to point out once again that Wolfgang Baur is a complete asshole MC. He suggests that if the PCs dare to attack the Queen of the Succubi, that she will dominate and enslave them all, and, I am quoting here, "this adventure can actually proceed normally". Otherwise once Malcanthet is under 100hp she runs away, taking the flask with her. It does suggest that being the thrall of the Queen of Succubi could add a "wrinkle" for "paladins and good clerics". YOU FUCKING THINK?!
Anyways, to the Blood Shallows to capture Obox-ob. They get to fight an aspect of Demogorgon here, a CR 19 creature that has 24 Outsider HD and thus is a fucking speedbump who tries to destroy the aspect of Obox-ob after the PCs cast Freedom in its general vicinity to free the aspect of Obox-ob. The flask is an iron flask, but one that specifically captures and commands demons. A DC 26 Will save is required to avoid being captured, which the Aspect of Obox-ob resists 80% of the time with his +22 Will save, yet the adventure says they can capture him in "one or two rounds".
Capturing Obox-ob prompts another attack by Demogorgon's agents, specifically a CR 19 Unique demon named Major Enderan and 4 lemorian lancers (CR 15 stone giant juju zombie fighter 5s) and 5 bodak tyrannosaurses.
From there, it's back to Pazunia, to recruit or kill General Bagromar, Clone of Hethradiah, one of Demogorgon's heads. An opposed Diplomacy check against Bagromar's +43 secures his alliance, or they have to fight him; a CR 23 Outsider with 27HD and 48 AC (11 touch), saves of +29/+23/+21, and no fly speed in an open space.
And that's Enemies of My Enemy. The fucking bullshit of Wolfgang Baur as a killer MC is evident in every fucking word.