Dragon Heist – Spring : Vault Entrace

I’m preparing to run my table through the “Dragon Season” phase of Dragon Heist on Spring setting, but there’s one thing that looks like its going to be a big problem: the entrance to the vault.

First off, it seems almost impossible to find. All they know is that its somewhere

But this is a super big map, with something like 15 rooms, only one square of one of which actually contains the door. Additionally its a hidden door with an DC 20 Perception check to notice. Not passive perception, but perception. They have to be actively looking for it. This from a table that hasn’t looked for (or found) a secret door in this campaign yet.

It seems exceedingly unlikely they’d manage to make a check in the right spot, and even if they do, most likely they won’t find it because the DC is so crazy high.

But it gets worse. Say I rule that the stone tells them exactly what square to search (pretty sure I’m actually going to have to do this). Well opening it requires a knock spell (which they don’t have), or a DC 30 strength check. Even the barbarian can’t make that without a nat 20.

How are they supposed to get in? Has anyone else run Spring, and if so, how did your table get past this?