Board Thread:General Discussion/@comment-28605250-20160616035032/@comment-26887879-20160616103416

Well, we don't know exactly when was Gaster scattered. According to Gaster's Followers it wasn't recent event, it took Asgore long time to find a new Royal Scientist. I mean, there definitely is a hint that Sans and Gaster are connected somehow, but there's not enough evidence to prove they worked together, it's mostly a fan theory... When Sans says "our reports" it might be him and Alphys. At the end of True Pacifist or when you get Queen Alpys ending, it's implied that Sans and Alphys know each other and work on something together. While Sans might be there only to help Alphys with Amalgamates, Alphys might know more than she lets on. After all, she's aware alternate universes exist.