Curse of Strahd
Luvash is the leader of the Vistani troupe that stole the magical gem from Gobnait’s hermitage. Gobnait tracked the troupe to just outside the Crooked Crow inn and, under cover of night and fog, broke into Luvash’s caravan. Holding the leader’s young child hostage at knifepoint, Gobnait demanded the return of the gem and, although she was given it, she and the Vistani did not part on the best of terms.
Some time later, you all unknowingly saved Luvash’s child from being drowned in Lake Zarovich. You returned him to the camp (although Gobnait wisely stayed outside the camp’s boundaries) and earned Luvash’s gratitude.
He told you that the Vistani can enter and leave the domain of Barovia at will; the mists are no barrier to them.