The door opened on its own. Peter was looking over a few texts, some heavy old books about Slayers and their abilities, how to fight them, and what to do when one was magically replaced with a far more evil version of herself. Okay, maybe the information wasn't that specific, but it would have been nice.
He glanced up, and said, "Little busy here, Gabe, whatcha need?" The work was distracting him from Sarah's lack of presence. He already missed her.