Madame Eva and Strahd form an alliance

Count Strahd von Zarovich gave Madame Eva a potion which grants immunity to the choking fog that surrounds the Village of Barovia. The formula is widely known by the Vistani. In return, they act as the Count's eyes and ears in other domains.

Data from the Ravenloft Catalogue

		Domains of Dread I, Strahd, The War Against Azalin
		Secrets of the Dread Realms - p10 Ravenloft Third Edition - p17 Domains of Dread - p16 Ravenloft Campaign Setting:Domains and Denizens - p99 Realm of Terror - p9,p36,p65 Ravenloft Gazetteer Volume I - pp17-18 I, Strahd, The War Against Azalin - pp47-65