In Curse Of Strahd, Yeska met the Pack when they visited the church, and was intimidated by the powerful adventurers. After confirming their good intentions, he confided to Ghalwin Forrester that he had told Milivoj about Lugdana Andral's bones beneath the church, and was horrified to learn that the grounds were no longer protected. The Pack later solved the issue, recovering the bones and healing Milivoj's Curse.
Orphaned as a young boy and placed in Saint Andral's Orphanage, Yeska grew up under the close watch of Klavdiya Bolachko, until he was selected to assist Father Lucian Petrovich at Saint Andral's Church. Yeska's job in the church, outside of holy-work as an altar boy, was to clean, to cook, and to accommodate guests. He had a quiet and helpful disposition, which caused the loose-lip Father to occasionally slip secrets to him.
The altar boy always did what was asked of him, especially for the church's temperamental gravedigger Milivoj Temesvari, who he both admired and feared. When a sick and desperate Milivoj repeatedly demanded that Yeska tell him where Saint Lugdana Andral's bones were kept, he eventually surrendered the secret, though was not sure why he had asked. Unknowingly, this resulted in the un-Consecration of the Church.