I've diverted from the main story to explore the Catacombs. I've gotten everything and killed the Champion. My problem is there's a cell that I can't seem to interact with. Is it that I'm not actually supposed to be here yet and it'll open later? I ask because I've scoured this place top to bottom and nuthin'.

The door in question is an "opens from the other side" type. Catacombs are incredibly confusing so very easy to get lost or run in circles.

@fredchuckdave: Thanks Fred. I read a few walkthroughs before asking and they didn't mention it. It also feels like I've gotten everything good from down there so I may just give it one more run before calling it a day and moving on.

@bill_mcneal: No problem. I'm trying (and failing) to chill on links but I do have an unfinished LP of Lords of the Fallen if you're curious, should be reasonably informative.