|Dates||???? – 2013 (killed by Sam Winchester)|
|Episode(s)||9.17 Mother's Little Helper|
Sister Agnes was possessed by a minion of Abaddon and tasked with the job of stealing souls to turn into demons in Milton, Illinois. Sister Agnes was the only other demon to evade exorcism during the encounter with Henry Winchester and Josie Sands at the St. Bonaventure Convent in Milton, Illinois in 1958.
A demon possesing Sister Agnes at St. Bonaventure Convent in Milton, Illinois has been working with Abaddon mining souls from people. When Sister Julia Wilkinson sees the Mother Superior dragging a woman down the the stairs she is knocked out and tied to a chair along with a small group of other people by Sister Agnes. One by one Agnes unties each person, taking them into the next room, where a flash of blue light appears, until only Sister Julia is left.
When Henry Winchester and Josie Sands arrive, Agnes is able to evade exorcism until Abaddon is able to knock Henry out and take possession of Josie. Once in Josie, Abaddon tells Agnes to play dead and wait for her return.
With Abaddon's campaign to take over Hell, Agnes returns to her work in Milton stealing souls to help create a demon army loyal to Abaddon. When Sam learns there is a connection to the soulless people in Milton and the St. Bonaventure Convent, he goes to the convent to investigate, where he comes face to face with Sister Agnes. Agnes tells Sam of Abaddon's plan and that the soul mining factory in Milton is only one of many. When Agnes threatens to rip Sam's soul from his body, Sam begins to attempt to exorcise the demon, however Agnes begins to choke him. That is when Sam pulls out his phone and plays a recording of the exorcism rites, throwing the phone across the room. Sister Agnes falls to the floor in pain and begins to crawl toward the phone trying to get there before the exorcism is complete. She is able to reach the phone and smashes it to bits. But before she can recover, Sam stabs her with Ruby's knife, killing her.