The quest text for this one is yet another case of weird, confusing quest text in Legion (I've noticed a lot, be they poor explanation or poor proofreading). The quest, which is the first in its mini-story, just has Morhun launching off talking about corruption to a complete stranger who walked up to him. It's like he was in the middle of the explanation.
What corruption? Where is this corruption? Is that why this character is out here? Who is this character? I mean, I can see his name, but he doesn't introduce himself. What happened to "Greetings traveler, I am Morhun Rivertamer of the Rivermane and I am here investigating a strange corruption detected within these waters..."?
There were a few others like this that I've encountered, a number of them in Stormheim (though I forget the names), but I remember one that was sending me towards Hrydshal which basically said 'the storm drakes are used as mounts by the vrykul, but storm dragons are allies to no one, so go make allies with them' and you end up learning that the two groups DID use to be allies.
Also there's the quest in Val'Sharah with the owlkin and Keeper Remulos where, without explanation, Keeper Remulos is suddenly dealing with them. As a druid it's especially confusing since he's supposed to be in your class hall. So again why is this character here? Why does nobody seem surprised that he's out here? Better explanations please!
Hoping they do some proofreading before 7.1. Return to Karazhan and Quest Text Proofreading!