While wearing a mask, Sean contacts Lee to meet him and the rest of The Family in the woods to exchange the book for Mo. During the exchange, Lee tricks him and is captured by The Rake while Mo escapes with the book.
He is first seen in the found footage of Dead Weight, where he is wearing a mask and arguing with his right-hand, Lex, and her boyfriend, Matthew about their role in capturing The Carrier (Lee). In the next scene, speaking to himself with distant voices in his head (presumably The Rake's), and promises to the voices that he will have "the Carrier's consent as soon as possible".
He is then seen preaching to the rest of The Family, about to let Matthew become a member. Instead, he pulls a gun out and executes Matthew and several cult members. This causes Lex to go into a fit, and The Speaker then locks her away in a storage unit, where he is also keeping Lee.
While still wearing the mask, tortures Lee in unimaginable ways while he is imprisoned. He has his finger cut off and shipped to his brother, Mo, and also has The Rake attack him. This causes Mo to go into an outrage and eventually tracks down Lee and rescues him, with the reluctant and temporary help of Lex. He also knocks out and captures Sean in the process.
Mo ties him up and takes off his mask, revealing him to be a friend of Lee named Sean. Lee goes into an outrage when he sees him, but Mo holds him back from doing anything hasty. Lee then explains to Mo all the horrible things that Sean did to him while he was imprisoned.
A month later, Lee interrogates Sean. Sean at firsts rambles about "what he needed to do", and "portals and rituals". He then mentions the name Linnie. When Lee questions who Linnie is, Sean simply throws his questions back at him and laughs. He also says that he did everything he did for "The Speaker". He also says that "The Speaker is everything and everywhere." After a few more sentences, the Speaker appears to be the Rake. He also said that The Speaker was going to make him a God. This gives Lee the conclusion that The Rake's whispering has brainwashed him. Lee then concludes that the best way to get his revenge is to leave him with his "withdrawal." He leaves him in the basement.
Sean is confirmed to still be alive in A Message, where Lee provokes The Family by stating that they still have Sean in their basement. Lee also says that he thinks about killing Sean everyday, but he won't, because he considers him "their leverage."
Lex eventually breaks into Lee's home with some Family members and talks with Sean. She reveals herself to be the new leader of The Family and proceeds to taunt Sean about being a much better leader than he ever was. She then leaves him for The Rake to kill.