>>718889364
I think it's likely. The Church is the closest building in town to The Shelter. Undyne being kidnapped first means there won't be any effective police response to more people disappearing.
Dess ran in and grabbed him in broad daylight (or, rain). She could have been ordered to make the move when Carol got the call about Susie finding the guitar (when talking on the phone earlier the plan was "church... tonight..." which makes it seem like things might have been expedited, but the plan was always to target the church). The Dark Fountain(s) were made and she waited for Kris to bring Susie there.
Alvin making the Fountain in the entrance gives some plausible explanation as to why that fountain was different (he's an old man and deeply unsure of himself, so he has less Determination than The Knight/Kris/Susie) and is the best explanation for how Gerson was resurrected, which Ralsei claims can only happen in very specific circumstances. (It's plausible that The Knight (Dess) also had a significant connection to Gerson, he was her teacher and probably a mentor to her too, but that's more of a stretch than the fountain just being made by his own son).
It's also possible that Alvin is in on the conspiracy in some way, like Asgore, and could have even been the one hiding in the back room the whole time, but that seems unlikely. I don't think Kris would directly ask Alvin about The Shelter in that case, and whether Alvin is in on it or not he's still a loose end to be tied up.
