Ok the key thing in all 4 scenarios is The Withering. Basically it's this curse God lays down that weakens vampires. Robs em of their disciplines and thins their blood. The amount of time it takes to work varies from scenario to scenario.
Scenario 1: Called Wormwood this is the shortest scenario. It takes about 40 days. God decides he's going to wipe out the vampire race and does so. In this one the characters have a chance at redemption by making it to a small abandoned church where they live for 40 days with each other and a group of other vampires. Ferox the Gargoyle is the leader of this santucary and created it at Gods command. In this story the Withering takes 40 days and comes in the form of a red fog. It doesn't breach the church so those inside are safe from it. Over 40 days the rest of vampire society dies slowly and painfully. Caine and everyone else, no exceptions. If during the 40 days the characters prove themselves worthy God turns em into humans, otherwise he obliterates them with the sun. Ferox for example is destroyed for pride. In this one vampires exist, and die without humans ever knowing they were there. It goes into alot of detail between the relationship of God and Caine, apparantly God did NOT curse Caine, Caine cursed himself in his own pride.
Scenario 2: Foul is Fair is about Lilith. Yes Lilith. She and a group of powerful antidilluvians, most of whom nobody ever heard of set out to destroy Caine. Among her group are Brujah, yes the real Brujah not Troile who apparantly escaped Diablerie by using Temporis to throw himself hundreds of years in the future. Also among them is Malaki the mortal sister of Malkav. Nosferatus brood mate is there and he makes Toreador look plain. Most noteable is The Crone. Yes the one from the Book of Nod that Caine staked. Apparantly SHE was actually the first woman not Lilith. At any rate Lilith has about 6-7 Antedilluvians working for her depending on what you count the Crone as being. Caine does indeed show up, along with Saolut, Nosferatu, Lasombra, and there are possible appearances of Abel and Lucifer, I'm not making this shit up Abel can show up if you want him to they list his profile as the first Wraith. Anyway this is my favorite one cause Lilith calls up a bunch of sea monsters(I'm serious) and they go at it in whatever city you want to put it in....oh yeah Lilith and Caine fighting it out in GASTONIA! But anyway Lilith won't hit Caine(remember that Rule of 7) so she lets someone else kill him, either Malaki or Nosferatu get to do it depending on the ST. If Abel shows up then he forgives Caine and then kills him. In this one the Withering works slower, and if your character sides with Lilith your immune from it and free to join her in her garden as something not quite vampire. Her blood protects her chosen vampires from Gods curse. In this one humans for the most part have no idea what's going on. The funny part is Lilith sends assasins after Augustus and Set. Augustus dies by Wraith assasins and Lilith tells the Silent Striders where Set was sleeping and they destroy him. YAY STRIDERS!
Scenario 3: This is the one where the Masquerade falls straight to hell and vampires become world know. Jan Pieterzoon plays a big part in this one. He tells off Hardestat and forms his own sect to destroy the antedilluvians. Ok in this one if your players join up with Jan and go through the plot they kill: Tzmisce(TWICE!), Tremere, and Augustus Giovanni. High points are seeing Pieterzoon on a talk show arguing with two human analysist about what vampires really are. The other big highlight is Set. Set is a big part in the second part of the scenario. He wipes out a large number of Setites upon being awoken in the second city(yes you get to go there.) He then along with Toreador, Gangrel, Malkav(who's 13 little boys singing in unison), Brujah, and Lasombra(who's not even remotely a vampire anymore set up a new city where they summon all their childer. Then they start looping off the heads of all members of the Sabbat, Inconnu, Jans new sect, and anyone else who's ever worked against them: Note this is like 95% of all vampires. A few vampires survive as their servants and minions. They round up the characters, Sascha Vykos(who looks like a human again) and a bunch of other guys. Well by this time the characters have Saulot with them, only Saulot is only a 6 year old little boy. Mind you he's got Caines blood in a vial though. This vial can only be drunk my a human, and whoever does gets the chance to sacrifice themselves for the sins of all vampires. In other words they get to be Jesus for bloodsuckers. Anyway Set being a right asshole wants to drink it and mocks Saulot. When Saulot tells him it'd kill him he forces the blood down Saulots throat. That's about the last mistake Set ever makes. Saulot becomes as powerful as Caine, for some reason Set sees this as an excuse to freak out and kills all 12 bodies Malkav was in killing that Antedilluvian off. Then down comes this angel which asks Saulot if he is willing to make the sacrifice. He says yeah and the angel blasts the city with a beam of light which kills the rest of the clan founders. Everyone else survives this though as it only does 5 levels of agg damage(oh come on it's the fist of God!) The Withering is still in effect, though it's taking years to act in this scenario, and eventually it kills off all vampires on Earth. The players however have a chance to become human again through repentance. In this one humans know vampires exist but don't go ballistic on them. My favorite part of this is the little side bar where Justin Achilli is going about "Yeah there you have it the Setites fucked up horribly and now Sets gonna rule us all now! Thanks assholes!"
Scenario 4: This is the balls to the wall battle we all wanted. In this one the Masquerade falls and all hell breaks loose. Humanity freaks and basically declares war on vampires. All countries do this not just the U.S. a few try to be civil for a while, but once they get to know what the Camarilla elders are really like....yeah you get the idea. The Ventrue, Toreador, and Setites wreak a God awful amount of damage on mortal society just by using their influence and power. Then the Setites perform a big ass ritual and try to wake up Set, thing is Set is already dead in this story. However being dead apparantly doesn't strip away your Dominate and he orders the entire clan to "join me." Within 2 nights the whole fucking clan commits suicide. AHAHAHAHAHA! I'm sorry I hated that clan. Well the death of the entire Setite clan wakes up the rest of the clan founders though. Nosferatu, Tremere, Toreador, Haqim, Malkav, Tzmisce, Lasombra, Saulot, and Gangrel all come roaring out of the ground and declare war on the nations of the world. Here's the fucked up part: They win. Weakend by the earlier fighting the worlds nations can't muster the technology to fight off the ancients. Thus each antedilluvian rules a part of the world. Except for Toreador whom White Wolf forgets to mention ruling anything. Saulot also doesn't rule anything as he's to busy being the vampire pacist. Any way for a while they rule, some for a few weeks, some for the better part of a year. But eventually one by one they fall. Tzmisce falls first, then Nosferatu. They all declare war on each other basically and go about it full scale. Nosferatu is riding around in the belly of this giant beast thing. Gangrel merges with the planet and they become one. Lasombra, who's not a vampire in any of the Scenarios, he's just this shadow thing becomes one with the abyss and departs. There's one ante called "The Shaper" who is rumored to be Brujah, but it to dies. The rest simply fall due to the Withering, except for Malkav who is the Malkavian Madness Network yet still somehow manages to get himself chopped into little pieces by something. Tremere tries to enslave the world using the true name of the human genome, but fucks it up and dies. In this one the Withering takes a while but eventually kills off the entire vampire race and you chances of being redeemed are so slim it's not even worth mentioning.
My personal opinion.
1. Now what's funny is Caine only shows up in the 2nd scenario. There is a little part about him in the back of the book explaining that it was his pride that kept him from ever interferring in the affairs of his children. He's been awake for basically the entire time he's existed and has known about everything. God has been waiting all this time just for Caine to ask for forgiveness so he could take Caine into heaven. He's been getting slowly pissed off at the way vampires have corrupted the world and wants to give humanity a chance to flourish on it's own. He's been waiting for Caine to set the matter right this whole time. He gave Caine 1 last chance to be the father he should have been to his children when Ravnos woke up, but alas Caine refused to stop Ravnos and it was humans who slew the beast. The whole relationship between God, Caine, Abel, and Lilith is one of the best things about the book.
2. I didn't like that in every scenario that mentions the antedilluvians Ventrue is already dead. And he died during the 2nd city. Now I know I've never been that big of a fan of the clan vocally but I always figured he'd be the guy to beat if the world ever did come to an end and all the big nasties went at each other. I mean really his clan is one of the most impressive ones out there. Anytime I groan to myself what a chore it is keeping the weirdos in the Guild in line I can always read some White Wolf fiction and find some poor schmuck Ventrue who's got it worse trying to keep the weirdos of the Camarilla in line. Alot of people think the clan is boring, but I like the idea of somebody who's got the brass balls to keep the Sabbat at bay and the Brujah in check. Plus they got organizational skills that make the Tremere look like a surly mob. This all comes from in my opinion their founder. But you never hear anything about the guy. Yeah Sets the ultimate evil and Tremere is a rat bastard, but Ventrue always got shitted in my opinion. I'd have liked to have seen him really come into his own here.
3. You can really tell White Wolf is making fun of all the power gaming tweeks out there. All the remarks they make like "All your vast powers aren't worth a shit against God" and the stats for the Antedilluvian power "Any Discipline Level 10: This power does whatever the antedilluvain wants it to do. System: It works cause the ST says so." These are clear shots aimed at the kind of gamers we all love to hate. I counted no less that 10 shots at power gamers.
4. I'm so happy the True Brujah are revealed to be the idiots I always knew they were. "Oh we're the True Brujah! We're not descended from Troile." Yeah they are. Brujah only embraced one childe and was never diablerized. The original Brujah Clanbook sums up the opinion I always had on Troile killing Brujah "So they expect us to believe it's possible to take on the founder of the most violent group of vampires ever on his home turf?"
5. The only thing that makes me happier than the True Brujah being revealed as total morons is the Setites doing them one better. It makes me so happy that the culmination of God only knows how many thousands of years to bring Set back and what's it do? It kills them all. BWAHAHAHAHAHAHAHAHAHAHA!!! I hate Setites, always have and always will. Nothing makes me happier than the thought of the look on their faces when they realize just what a group of universal fuck ups they all are. "Oh yeah lets bring back the dark god and he'll no doubt be so happy with us he won't kill us! What? He's back? He hates our guts? He's coming to kill us all? NOOOOOOOOOOO!!!!! I shoulda been a Ventrue!!!!!!"