The Cave of Portals is an area in Divinity: Original Sin. It is located at the foot of a hill, just southwest of Sacred Stone in the eastern half of Luculla forest.
- Enter the cave and proceed to the next area by interacting with the ladder at the end (there's nothing of interest here).
- This area contains several portals: a return portal, frozen portal, fire portal, an obfuscated air portal and the library portal in the distance, which is where you want to end up.
- Head to the bottom right of the map where a skeleton and book can be found. Read the 2nd page of the Scribbled Notes to find the sequence in which to use the portals, which is as follows:
- "Brr!" refers to the frozen portal at the top left of the map. This will take you to another room of portals with a water portal, earth portal and bronze portal.
- "Mountain" refers to the earth portal at the bottom left where rocks can be found in the room. This will take you back to the original room at the return portal.
- "*Pant*" refers to the fire portal in the center right.
- "Waterfall" refers to the water portal with the waterfall behind it.
- "Mop" refers to the hidden air portal at the top of the map. The wall has an arch obscured by a hanging cloth. Just walk through it.
- "Bronze" refers to the portal in the center right room with gears and machinery.
- This will take you to the library with many bookshelves and three altars with skillbooks. When you approach the altars, the ghost of an Immaculate will appear and tell you that you can only choose one skillbook as your reward. Pick one book and the other two will vanish in smoke.
- If you learn the skills before you pick them up you can "use" all three skillbooks (could not replicate in v1.0.252)
- Tthe second in the series of chests for the quest The Last Chest is found in the library.
- Pulling the lever beside the final portal allows you to use the original return portal to send you directly to the library.
- Choice of one of three random Master level skillbooks.
- 3600 XP