I was running a long-term modern day GURPS supernatural/superhero/conspiracy/special ops campaign, where the fact that there were people (and other entities) with superpowers was a secret to the world at large. Thus, PCs were concerned with keeping their powers on the QT. I was also using mysterious prophecies, shifting alliances, groups-within-groups, and lots of long-term plotting & clue-planting. It may be the best game I ever ran, and it ran for a decade or so.
So, the PCs had previously heard rumors that, somewhere in the world, there was a centuries-old (at least) immortal, dubbed "Enigma". It was a legend, part of a prophecy. The PCs know that the shadowy villainous conspiracy they oppose wants to find Enigma, and take him out. The PCs' organization is also really interested in finding him, mainly because the bad guys seem to want him out of the picture. (The NPCs all referred to the alleged immortal with male pronouns.)
Another, separate (seeming), mystery involves one of the PC's backgrounds; this PC was, power-wise, a Wolverine clone -- claws, regeneration, etc. Origin-wise, he was the result of pre-WWII Nazi experiments, intended to create ubermensch. (I don't remember when the PCs knew that Enigma had something to do with said experiments; they might have known.) Important thing that the PCs didn't know: unlike the PC, the Enigma could control "his" regeneration powers.
The PCs had also learned that there was a nurse that might have worked on the experiments that had fled Germany, and been pursued various places. They eventually want to track down where she ended up, as she may have left useful info.
This is all spread out over weeks or months, and many sessions, and interwoven with other adventures, mysteries, and fights. Also, lots of ninjas.
So now the PCs are once again dealing with an arms-smuggling gang in SoCal that seem to have some sort of ultra-tech or magical healing gizmo. Several of them have been seen to hit themselves with autoinjectors full of quick-heal drugs. This is a tech that the bad guys have, but the good guys don't -- and said good guys would like it, as GURPS combat can be painful.
The PCs have had a few violent encounters with the gang, trading shots (sword, bullet, etc.) and getting a bit frustrated (especially the katana-wielding PC) that the leader always manages to escape, thanks in some part to her use of the quick-heal injectors (note here that the gang leader has never ever regenerated in any way, except after using the quick-heals). They finally decide to negotiate with her, to find out her source for the quick-heals, and try to get some for themselves; they manage to have a less violent meeting. PCs and gang leader parley a bit, verbally sparring.
Then the player of the nigh-immortal PC begins to think aloud, and proceeds to tie the missing nurse to the gang leader (I can't recall the chain of evidence now -- this was more than a decade ago!); but the player & PC conclude that the gang leader is in fact the nurse who fled Germany. "But that was 50 years ago, and you don't look that old. So you'd have to be . . . You're Enigma!"
I did not expect anyone to figure that out for a long time, as I didn't realize there were anywhere near enough clues for anyone to tie it all together; I had done my best to toss in enough red herrings to make it seem like the nurse could have, at best, identified Enigma. In fact, I'm pretty sure there weren't the clues to do it; the player just made the intuitive leap. And nailed it.
I was floored.
The fact that the katana-wielding PC decided to simultaneously shutdown the Enigma's protests and denials, and vent her (the player character's) frustration, in one fell "I run her through with my sword" swoop was just icing on the cake.
It was frikkin' awesome.
(FWIW, from the other thread, the arcane archer & katana woman had the same player; the cloudkilling wizard and the claws-and-regen guy were the same player.)
