With that business with Miraak complete, Ararvyne decided to secure himself an anchor on Solstheim with which to carry out his planning. Completing some jobs for Raven Rock, dealing with a coup d'etat, and he'd gotten himself a very fine manor with all the necessities included. And it didn't cost him a single bit of coin either!
Now that he'd secured himself a base of operations on the island, the time came for his final task: Collecting the remaining Black Books. Hermaeus Mora had given him this task, with the confirmation that the knowledge he sought, the formation and history of the Templars, would be within them. Thus he would request Neloth's assistance in Tel Mithryn (and even ass kiss a little to get his Black Book). For the secrets, he could endure.