Where is the Spider rune

[Happy Birthday Problem]

[Fel]

The spider rune is the only "exception" since you need to progress quite a bit further than the area unlocked by the previous rune, specifically you want to go to the slumbering sanctuary.

In this guide you have a "map" of all zones at the top and the path needed for each rune in "unlock runes" so it should help if you are not sure:
https://steamcommunity.com/sharedfiles/filedetails/?id=1214490016

[Happy Birthday Problem]

ah yeah the slumbering sanctuary i alrdy was one time there