Theory. Bishop is the chapter 4 boss. "A bishop is a senior member of the Christian clergy," which means that the chapter 4 dark world is in the hometown church and that the companion in the church is going to be Catti; considering that she is into cult stuff, it makes sense. Also, we can confirm that chapter 4 takes place on a Sunday because Susie and Kris have a sleepover, and usually sleepovers happen on Saturdays and Sundays, but because they went to school the previous day it would be on a Saturday. Though the church is relatively small compared to Kris's house, so they might have 2 dark worlds on Sunday, to make up for that small dark world.