To get the Artifact you have to get a bunch of fish, unsurprisingly, and at one point you will get a Luminous Pearl which starts you off on a quest to take it Khadgar.
You go talk to Khadgar and despite the pearl feeling magical to you, he COMPLETELY brushes it off and is like "go fuck off retard I don't care about fishing" which is amusing but we all know Khadgar is a pretty shit mage most of the time and this not being tomes he doesn't give a shit. He tells you to go to the Dalaran fountain.
So you go to the Dalaran fountain and the lady there tells you to go right ahead and throw it in the fountain cause it's pretty. The pearl, instead of sinking in the fountain just starts floating above it. The same model
(not really surprising considering blizzard loves re-using things) can be found at the bottom of the ocean of that
Top 10 Creepy Things in WoW video that was posted a few posts up.
So you toss it in the fountain, and out of fuckin' nowhere Nat Pagle magically appears behind you and runs up to you in a panic, to give you this quest.
When you're there, Nat Pagle wants you to kill every singing Murloc on the island that you arrive at. Eventually after doing so, you and Nat will fish up a big ugly looking Murloc that you kill, and after killing he takes all the bones to make your fishing pole. You bring the bones to the lady at the fountain in Dalaran and
The fuckin' dead thing that Nat Pagle wanted you so desperately to murder starts to "resonate" with the pearl. I mean we all just accept Nat Pagle as a friend but in Blizzard fashion, like they did with Gamon, would it really surprise you if he turned out to be a bigger plot to the story than we think in an expansion?
Also important to note, this weird magical pearl is now floating above a fountain in a city full of magic. Doesn't seem that out of place, but what if that magic is just what is needed to bring N'Zoth forth? In an expansion focusing on the Broken Isles where we know Queen Azshara even makes an appearance at one point, who likely became a Naga after interacting with N'Zoth, I don't think it's that far fetched that at some point we're going to run into an Old God based in the Sea.
It's even speculated that the real reason for the Emerald Nightmare is because of N'Zoth, not because of Xavius, because in the book Stormrage it's said that Xavius is merely a pawn of "greater evil". N'Zoth is also known as the corrupter and obviously the Emerald Nightmare is a corrupted version of the Emerald Dream.
.....of course this likely isn't the case at all but it's fun to dream. IT'S FUN TO DREAM DAMN IT.