What level are the characters?
Got any other, non-spoiler details? What has happened so far?
The pcs vary in level; the top level guys are currently 27th, with one guy who rarely makes it at 21st. But he's got an exceptional +6 bow (he's a seeker) that helps make up some of the difference.
Hmm, the story so far is... complicated. There are two main elements, which have grown somewhat intertwined since the pcs last messed with either one.
Thread 1: Tenebrous and his lackeys.
Since the early levels, the pcs have been dealing with the lackeys of an entity calling itself Tenebrous. From what they've learned, it's some sort of vestige of a dead god or something, and its lackeys have been trying to bring it back to life (or help it come back to life). To do this, they've been seeking...
something that neither they, nor the pcs, can identify. (At least until recently.) This 'something' appears to be an artifact tied to Tenebrous' former existence; but all memory of it was wiped from the multiverse via an epic ritual involving the River Styx.
The pcs' initial foe was a half-ogre named Quah-Nomag, who eventually tried to discover the identity of the 'something' by going to the Mountain of Ultimate Winter, a part of the Elemental Chaos so cold that even creatures normally immune to cold freeze to death, so cold that even thoughts and ideas freeze into ice crystals there. They stopped Quah-Nomag by triggering a massive avalanche that buried him and the crystal in question (somewhere in the mess), slaying him and leaving the crystal irretrievable.
However, Tenebrous' cult has continued to work on finding an alternative method of tracking the 'something' down. The current head of the cult finally realized that they needed to talk to someone immune to the powers of the Styx- and that means Charon. The pcs found a letter that revealed this, but have ignored it for months, giving the cultists plenty of time to get ahead of their plan.
Along the way, Tenebrous itself has been desperately seeking the 'something' itself, slaying several gods with the power of the Final Word, one of the mythical Words of Creation, but the Final Word is so powerful and so toxic that it's slowly destroying Tenebrous. It slew Primus and impersonated him for a time, sending the modrons on the Great Modron March early; it destroyed a mind flayer deity to sieve through its memories and knowledge; and so forth.
Thread 2: Fray and her plans for the timestream.
The pcs have another arch-foe, but this requires a little campaign backstory to make any sense.
So let's start with the fact that there was a previous multiverse, but it was eaten by Tharizdun. The short version is (and believe me, this IS the short version), there was an infinite dungeon quasi/demiplane called Darkhold that managed to leave Nature before Tharizdun devoured it. A few individuals were in it at the time and were saved, including three bound gods, one of whom was the god of illusions of the world that was at the center of the old multiverse, and one of Tharizdun's mightiest servants, an Angel of the Apocalypse, who was trapped. The place also has a lord known only as the Master of Darkhold.
The Master of Darkhold, among other things, ran multiverse simulations in his infinite (yet still very limited) home. This was partially out of boredom and partially an attempt to figure out how a multiverse could exist sans Tharizdun, or could bind Tharizdun in a truly eternal fashion, rather than in a fashion in which his eventual escape was fundamentally inevitable.
My current campaign setting began as one of these simulations. Eventually, the bound god of illusion managed to sneak his staff into the simulation, which, among other things, had the ability to lead people to him: if it was balanced on a finger and spun, it would always end up pointing the same way- toward its master. The possessors of it eventually discovered this, followed it to an entrance to Darkhold, and found him... along with the other two bound gods, and the Master of Darkhold. Meanwhile, they accidentally released the trapped Angel of the Apocalypse into their reality.
The adventurers (pcs back in 2e) learned that they weren't really real, and with the AotA in their multiverse but still trapped inside Darkhold, the Master of Darkhold was planning on simply writing that simulation off. Which meant their multiverse would be destroyed by the released AotA. They managed to persuade the MoDH into letting them try to make their world real- the only way they had a chance, albeit a slim one, of standing against the AotA. Doing so required that they slip back in time to before the moment of Tharizdun's triumph in the
real, but now destroyed, multiverse, where they could gather a number of extremely powerful artifacts to use against the AotA and the materials necessary to try to jumpstart the birth of a new Nature. One of these was a gigantic piece of a moon that had been destroyed by a group of 1e pcs waaaaaaay back in the day (it really could have been any piece of nature of that size, but where else you gonna find a free-floating piece of stuff hundreds of miles in diameter that nobody's gonna miss?).
It was crucial that they not disturb the timeline of the old world, thereby alerting Tharizdun to their presence. This part, they utterly failed at.
Anyway, they managed to get their material components and one of their artifact weapons and escape back into Darkhold, and the new Nature was created, making their world real. The MoDH slammed the door (so to speak) on the old multiverse's ashes, but several other AotA managed to make their way into the new multiverse first, leaving a tenuous bridge between the two multiverses.
So the 2e pcs slew the AotA that had first entered their world and another group later eliminated a secon one. The third one to make it over has yet to be found/dealt with.
Okay, so moving ahead, a later, different group of adventurers found an abandoned but sealed temporal door that connected to the old multiverse, unsealed it for a few moments and talked to a god on the other side named Maltar, who passed two artifacts through to them. Unbeknownst to those pcs, the artifacts would enable that god to eventually possess and take over their users, letting him escape into their multiverse and survive the end of all things.
HOWEVER, their conversation with him took place, in his timeline, BEFORE the 2e pcs had finished their mission. This changed the old timeline even more, and that god's arch-foe, Fray, who had learned the trick of creating the sort of artifact that would possess and transform someone into her after her death, managed to slip her own amulet artifact into the pocket (so to speak) of one of the other individuals to escape the old multiverse before its death... which eventually made its way into the current campaign setting. I'm leaving out a lot of minutia here...
So now we come to Fray.
Fray is a very powerful wizard villain who goes back to the 1e days in my old (eaten) campaign setting. She's extremely intelligent, very savvy and highly tricky. Once she figured out the whole situation, she was delighted to be in a multiverse free of Tharizdun's influence (as far as she knows- she doesn't know about the remaining AotA), and determined to ensure that T could never reach it.
Doing that requires that she manipulate the timeline so that the door that let Maltar pass his artifacts through never existed. She needs to acquire enough mastery of chronomancy to go back and prevent it from being made in the first place, which will simultaneously keep her worst enemy from existing in the current timeline and cut off the strongest remaining connection to the old multiverse.
However, since Maltar's passing of his artifacts to the new multiverse is what alerted her to the need to cross over herself, the only way to do it without also eliminating her own presence is to usurp the power of the goddess of time.
Now then: The new multiverse's timeline is shaped like a Moebius strip, but it has a hole in it. This 'hole in time' is something that various groups of pcs have been aware of for a long time, but it has previously always been an academic matter, like the wobble in the Sun's orbit. To Fray, it's an opportunity. The current goddess of time, Coila, can ensure that the multiverse circles around the hole without damage, but during that period, she is distracted and all her power is focused on preventing the multiverse from swirling down the chronal drain.
Fray intends to use that moment of distraction to strike. Somehow- the pcs don't know how yet- she and Tenebrous have decided to work together. The pcs have driven her away from her initial base, which was a moon that was actually the huge piece of the old Nature that was used as a 'seed' to jumpstart a new Nature/multiverse into reality, and claimed it for their own. But the first time they faced her, using archaic magic (e.g. 20d6 fireballs), she beat the hell out of them and they had to flee for their lives. A second confrontation went better, but not by much, for them, and both sides ended up retreating.
Now the pcs know that there are overwhelming forces at the corpse of Tenebrous, somewhere in the Astral Sea. They have been warned repeatedly that their best chance will come when the bad guys are at the moment of their triumph- and boy, is that true!- but that, even then, the odds are.... poor.
Yay for confronting unbeatable odds!
This whole thing goes back over 25 years, real time, and all the way to stuff that happened in my 1st Edition game when 1e was the 'current' edition.
