You will never believe it, but I'm under an NDA that prevents me from talking about the endgame.

Wait! What?! This was a LOL moment for me. Made me think you Americans really live in Sea-Dracula-land. :D

Trouble Snowballs, part - is this part 4 perhaps? When Trouble Finds 'em + Is It All Connected?

My thought process as described so far provides a nice picture of who the movers and shakers are, what they've done so far and what they're about to do.

Knowing "what they're about to do" (i.e. anticipating my own characters' moves) means I'm equipped for "driving with bangs" - and that's what I did to start session #2, when Kamrissa just appeared at Nictus's door and basically said: "Hello there, you with a Reputation, who was the easiest to find. Take me to your friend who owes me one." Afterwards, while I could have started all sessions like this, I refrained from doing that and allowed them the initiative instead. Next time, though, I may opt for a change of pace and do that again - I pretty much know who's going to be at their door next, for each of them.

"Having trouble find 'em" is one of my moves, and other than as a beginning of session move I'm always waiting for my turn in the conversation to bring it, especially when they roll a failure on their moves.
Of course, part of the game happens at a closer, zoomed in, "tactical" scale where, when they roll a failure, it's obvious what's going to happen. When Vetin's attempt to Interrupt a meddling not-really-a-noblewoman from casting a spell went awry, say, I didn't have to think about which move to make: the spell went off - and, as it was an Irresistible Slumber spell, Vetin just dropped unconscious, lights out.
But part of the game happens from a more zoomed-out perspective, a bird-eye view or at "strategical" scale. When the PCs are scattered around the city and want to rejoin and they fail their Recover, Regroup & Prepare roll, or when Nictus and Dix are sitting under a bridge amongst the city's lowlife with Kamrissa's dead body wrapped in a carpet, waiting for the perfect moment to just leave it there and get away with nobody paying attention to them, and I ask for a Patient save and they fail it... That's when I have trouble find 'em.

To have trouble find 'em I usually browse through my notebook looking for the most applicable piece of trouble, then have it make a move against the PCs. Usually this requires choosing (or, less commonly, making up) a suitable NPC for the trouble to make a move through. Most of the time, having a PC meet said NPC is hard enough a move - a charged interaction, potentially though not outright dangerous, which interrupts whatever they were trying to do.
Sometimes I can't immediately find a connection with existing trouble or NPCs, though, and I improvise something on the spot. When I do so, I tend to operate "color first": what kind of encounter would fit the sword & sorcery genre? What's missing from the current situation, or we haven't had enough of so far? I ad-lib everything according to a sketch of a plan which starts forming in my mind... Later, between sessions, I give this "random" encounter the same treatment I gave the first scene, looking for trouble uphill, snowing down more trouble from there, considering the middle link of not-so-powerful people who can still fuck it up royally. I revisit whatever outline of a "plan" I had, reinforcing it or changing it as I see fit, stopping at nothing short of blatant contradiction.

For example, in the corpse-disposal situation I described above, under a great bridge, either Dix or Nictus failed one of their saves to go unnoticed. I had already mentioned smoke-drinkers and pushers as part of the derelict humanity crowding the scene, and for some reason - probably because of a song I'd had on my mind - I had noted that our game hadn't had any dwarf NPCs yet. So, naturally, I made up an NPC - a shady dwarf who was a drinking-smoke pusher - and had him approach the PCs to meddle. Stuff like: "Hey, are you new to this? Because your carpet is leaking blood - it's obvious you're doing it wrong. Do you need any help there?"
They of course Demanded to be left alone, and what's interesting about Demand as a move is that, even on a full hit, I still have to look for applicable trouble to bring to bear. "Sure," I said, "he'll leave you alone and maybe even keep his mouth shut about it (but no promises), if you do something for him in return. He just wants you to keep an item for him until tomorrow." I was totally ad-libbing. I had this idea that the dwarf was involved with a very big and powerful smoke trafficking gang and that he'd stolen something from his own bosses, but currently he was trying to escape purchase and not having the thing on himself when they'd finally get him was his current priority. The PCs having agreed to his terms, I described a masterwork Chinaware container in the shape of a skull, with a keyhole and seam but no key to be seen - I was totally ad-libbing, with just a half-formed idea on my mind, and the closed container was of course my stalling tactic.
Later in that quite eventful session, Dix and Nictus were facing an enraged necromancer gone on a murderous spree (this was Barabas the butcher, deceased Tinius's long-time partner in crime) and his host of ghostly helpers - a dire predicament indeed. Dix was thrown down a stairway, rolled successfully to Recover, Regroup & Prepare and chose to check his own equipment as one of his options (it was quite important in the moment to establish where Dix's long knife was, as he had been Barabas's hostage just moments before). I saw a golden opportunity on a silver plate to tie it all together like a nice swords & sorcery tale, and told the player the Chinaware skull had broken open in the fall. I was ad-libbing based on my half-formed plan. I said the broken container was full of ashes and, in the heat of the moment, of course Dix went for a quick act of necromancy to summon the ghost of the deceased - he knew they needed all the help they could muster to defeat Barabas. Thus the pact between Dix the reluctant necromancer and the ghost of Rasluius Duendel was born (the first name I threw together from random syllables as usual, in the heat of the moment; a surname I added later, and found a good reason why the ghost hadn't mentioned it).
It was later, between sessions, that I connected the dots, doing of these events what I had done of the first scene, inventing details and climbing uphill and everything. I established vivid, concrete details about drinking smoke, its commerce in Vanetys, the Duendel family and the Dreamsellers cartel, the factions they've split up into, as well as a biography of Rasluius. Irony is, Dix and Nictus are characterized as being not from around town, and they also keep Dix's necromancy skill a secret from Vetin and Iago, who are from around town: if they heard the name Rasluius Duendel, they'd immediately know Dix is walking around with basically the ghost of Al Capone (if Al Capone had never been caught and had retired to his own castle to die of old age). I retrospectively established a lot of trouble, including who commissioned the theft of Rasluius's urn and why.

This way I created what amounts to a whole new "front", linked to the already existing ones via one node only: the PCs. Eventually, as I build upon them, these separate sources of trouble are going to intertwine in ways, but I definitely don't feel a need to artificially join it all into a big conspiracy: it's just the PCs' lifestyle that attracts trouble like a lightning rod. In a sense, though, it's all part of the same, huge snowball: it was a failed saving throw they rolled while trying to dispose of Kamrissa's body (the character who had attacked them in the very first scene!) that brought the stolen urn into play. At this rate, I don't think I'll ever need to roll up a new "starting situation": the snowball's going to keep splitting into more snowballs and roll on forever.

* When different characters encounter different kinds of trouble, consider how they might have been - ultimately - caused by a larger, common problem, higher up in the ranks of the City.

Definitely!
I promise I'll get to this part, too. Or have I already? Well, anyway: an effect of the methods of prep I'm using (and I'm trying to describe in this thread) is that everything eventually ends up being connected with everything else. Or maybe that's just how I generally see the world (the real world, I mean)?

* The characters are all friends, but with lives and ambitions of their own. When you sit down to play this game, you're going to be playing the bits where their lives intersect. Feel free to zoom back and forth in time to focus on those times in their lives.

I like that! That's not how I'm playing, but I like the idea.

They're explicitly neighbors and friends who see each other and hang out together all the time.

Oh, by the way...! I pretty much missed that line (it only appears once in the current draft text, if I recall correctly) which says the PCs are each other's friends when I was running them through character creation, which of course added an extra layer of murky to our first scene recounted above. I noticed that after 1st session and we easily managed to ret-con that bit in (we actually established that not all of them had known all of the others before that fateful night at the House of Blue Steps, but that was a significant enough event to bring them all close together).

How did this pan out in your game? Did the players assume a "party" mentality, or do you follow each character around, a la AW, or something else?

I do follow each of them around (my "default" GM mode, unless otherwise specified by the rules), but they do spend a lot of time together... Well, not all together, really: more like in pairs and threes. There's something of a Fiasco-esque feeling about it. A routine has set in where I start a session by asking them what they're doing and, often, the answer is that they all regroup at someone or someone else's place to make a plan together. They talk a bunch, disagree on priorities or over moral issues or something - or occasionally say they agree but don't really act like it - then usually two of them go away on separate errands or escapades, asking one or two friends for their help.
For example, last Sunday they basically split into two separate "adventures": Dix had to fulfill an obligation to some ghost (as usual) by relocating an urn to a princely mausoleum, and the warden of that mausoleum had asked his help dealing with a dangerous poltergeist-like ghost in return, so he asked for Nictus's help and they went to the mausoleum together. Meanwhile, Iago and Vetin went on a get-rich-quick-scheme spree: after starting a publishing house for pornography and satire at his run-down house (as the result of examining treasure), Iago went back to the House of Blue Steps to brief with and squeeze some more riches out of the Hostess in Black. There, Vetin, who'd just tagged along, heard that the master of the house was looking for -er- human resources to test the new magical defenses he'd had installed by the wizard Aktebeth. Vetin and Iago decided to turn labor-providers and started scouring smoke-drinking dens for people desperate enough to accept the job and sign off the biggest share of the reward to them (basically, we played a Hand to Mouth scenario from the perspective of the middlemen instead of the jobbers).
We played these two very different "adventures" at once, framing alternating scenes between the two pairs of PCs. I made the best of Vincent's suggestion from some other thread to disregard "naturalistic" time simultaneity and happily contrasted a single "round" of fighting against a dangerous ghost with half an evening's worth of Iago and Vetin (now aptly nicknamed "Cat and Fox" in table chatter) conning poor fellows into what they believed was certain doom. The most interesting part was in fact the thematic contrast, centered around issues of morality. On a side of the table, it all revolved around naive Dix trying to "do the right thing" in humane terms and grim, grumpy Nictus reluctantly playing along, showing a bit of his human side - on the other, Iago and Vetin were being perfect amoral bastards and had us rolling on the floor laughing at their bold ideas and blatant lies.

Quite unusually for us, we've played sessions of this game with one or even two players missing. The setup of the game makes it easy to rationalize this: reasons for a PC to be absent from the action which don't sound far-fetched abound, and it makes sense to focus on the deeds of just one or two PCs from time to time. Then, when we next all get together, the social ritual of briefing them about the events they missed turns into a very playful, pleasurable moment - probably because everything there's to say usually sounds like implausible or humorous tall tales! In fact, some players have been texting absent players mid-game, reporting events in a joking or self-mocking way: "You wouldn't believe how fucked up this is", and so on.

I don't know. I mean, I think we followed the procedure pretty much as intended, so the problem may be just that the procedure didn't "click" for us. If I did it again, it would probably be with a different set of people, so it may go differently.
But, overall, I think our game is doing really well, which means that setup procedure - clunky or not - has ultimately done its job of getting us started. I don't anticipate I'll ever need to revisit it during the current game, with the snowball of trouble already rolling.

Awesome!

Trouble Snowballs, part 3: small links in a chain of trouble

By tracking back the initial situation and other 1st session events to the powerful people who'd made troublesome decisions, and having them make malicious or thoughtless decisions again, by the time we sat down to play the 2nd session I had a lot waiting to happen: the Hostess in Black trying to get Iago to fight a gang-war for her, an annoyed Magistrate Vettonius mobilizing his forces to find Vetin - to ask her how did she know he was at the party (she didn't), some priestess somewhere still having a rival unmurdered to take care of, and of course the Pious Brotherhood making their next move...

But that didn't account for everything. There were actions wanting for consequences. For example, when the PCs - after Iago and Kamrissa exchanging volleys of crossbow bolts to no avail - Demanded that Kamrissa ceased her attack and retreated, it wasn't enough to deceive her (Vetin's "Lord Vettonius would be displeased" trick), but they owed her for it too: specifically, it was Dix, the reluctant necromancer, who shouldered this (I don't even remember who had rolled and who was helping with the move - that was a collective effort). There was an exchange like:

Dix: Leave us alone and I'll pay you back, somehow.
Kamrissa: You?! How?
Dix: We'll find a way. I always pay my debts.
Kamrissa: I'll know how to find you, kid.

What counts as Trouble, exactly?

To create trouble, have a powerful person make a thoughtless or malicious decision and follow through on it, to bad effect on people less powerful.

Alright, then the real question is: who counts as a "powerful person"?
So far in this thread, I've more-or-less followed the Job Framework in Hand to Mouth in the City of Nephthys, with its powerful persons of the 1st rank and the 2nd rank: a governor of the city, the priests of a powerful cult, gang bosses and lords of the underworld, the owners of a well-established house of luxury, people related in various ways to one of the city's princely families... That was great, a source of inspiration, and provided me with hints to a whole other part of my duties: adding vivid and concrete detail.
However, while thinking about how Trouble and its consequences snowball, and how PCs are caught in the snowball, it occurred me that this is a chain with a lot of links - that sometimes people not generally in a position of power get to make decisions which "steer" the snowball. I arrived to the following working definition:

• Powerful person: a powerful person is, for the purpose of game prep, anybody who's - even temporarily - in a position such that, if they make a thoughtless or malicious decision and follow through on it, it will adversely affect people currently less powerful.

Once we're on this train of thought, we can start following other threads: threads which have to do with Kamrissa's poor decisions and with Tinius the necromancer. By following these threads uphill I'm sure I can find an answer to one of the most pressing questions: what will Kamrissa, The Hand that Taketh, the ruthless enforcer of the Pious Brotherhood, ask of peaceful Dix? The answer ended up driving our 2nd session and colliding with other snowballs to make a storm.

[TO BE CONTINUED]

Trouble Snowballs, part 1: tracking the 1st session snowball uphill

Told you one important thing in my notebook is Trouble. Most of the time it's a note written on a left-hand page, marked with a little bubble with the word TROUBLE in it. Ex.:

TROUBLE: Magistrate Vettonius Arduino Komtec was actually at the party at the House of Blue Steps, disguised as a slave, to spend some time with a younger male lover.

For someone of his standing, that counts as a thoughtless decision.

How does this come to be?
After the first session (which, remember, was just one extended scene involving conflicts with multiple NPCs, plus a little follow-up scene involving wounded Vetin and one additional NPC) I sat down thinking and tried to rationalize everything which had just happened "on screen" as the consequences of unseen Trouble - that's what the booklet told me to do. Sort of tracking the snowball uphill. It wasn't hard, really.
First thing, there was Kamrissa, the enforcer, who was a gang member (a gang running a gambling racket: I'd stated that as public knowledge), had attacked a house of luxury during a party, wounding Vetin, and who'd also "stolen" a job - a murder - from Iago. It wouldn't make sense to me if Kamrissa's gang, the Pious Brotherhood aka Half-Bat, had thought of hiring Iago before deciding on using their own enforcers, nor did it make any sense to me that Vetin was a target (remember how these two details had come from players answering my setup questions - and were in fact at odd angles with what I had on my mind a minute before that, when I started setting the scene). I went for what was to me the most logical explanation: Kamrissa was carrying out two jobs at once! That's two pieces of Trouble, right here:

• the bosses of the Pious Brotherhood (powerful people) ordering Kamrissa to make an example of the House of Blue Steps: to storm the establishment slaughtering guests and staff (an outright malicious decision); and
• some other powerful person ordering the murder of somebody who just happened to be a guest of the House that night (malicious); first contacting Iago to do the job, but then changing their mind and hiring Kamrissa (thoughtless).

Hey, in retrospect, that's actually three pieces of Trouble. And two separate threads I had to explore, to follow uphill to their source.

A third such thread concerned Vettonius... This name had been made up on the spot by Vetin's player, when Demanding that Kamrissa ceased her attack. The roll was a mixed success and one of the conditions I dictated was "if you deceive them". Vetin's bluff consisted of literally saying: "Lord Vettonius would be very disappointed" - "That's just a name I made up", Enrico added out of character, "but I hope this sounds threatening enough". Since the bluff sort-of worked, I felt it was too good an opportunity to pass, and I made a mental note that "Vettonius" probably wasn't a name Vetin made up, but rather a name which was on her mind because she'd heard it somewhere - a name nearly unconsciously associated with power. That was entirely my idea, not required nor suggested in any way by the rules of the game, but I felt like I had to do something to add weight to what would otherwise have been quite a cheap throwaway use of part of a move. I acted on this thought by doing my job, that is, by introducing and playing NPCs - specifically, a guest of the house going by the name of Lady Luillia ("that's quite a common name", I added, "and doesn't necessarily have to be her real one") who visited Vetin in the servants' quarters, where she was resting and recovering from her wound, and graciously but excitedly asked her:
"I've heard from somebody who's heard from someone in the kitchen staff you've dropped the name of Lord Vettonius, just minutes ago. By any chance, is he here, at the House, tonight?"
(This also created an opportunity for treasure - as a bribe or reward from the lady. I'm glad this happened, because otherwise we'd totally have been missing out on an Examine Treasure moment at the end of our - relatively short - first session.)

[TO BE CONTINUED - next up: Even further uphill]

I'm more of an advocate for adjusting to it, if at all possible. I suppose it's too early to say.