The Forbidden Archives is one of those dungeons that looks simple until you spend ten minutes staring at identical bookshelves wondering where a single book could possibly be hiding. The Grimorium Obscurum is sitting in plain sight once you know where to look, but the path to reach it involves jump pads, flying books, and a boss fight that ambushes you the moment you think you're done. This guide walks you through the entire dungeon in Mortal Shell II so nothing catches you off guard.
How do you access the Forbidden Archives?
The Forbidden Archives is a dungeon tied to your progression through the Ruins of Mammon. You're working toward cleansing three more Corrupt Gates in this region, and the southern Corrupt Gate has a beacon next to it called the Gate of Infinity Beacon. That beacon is your entry point.
Step inside and you'll find a chest immediately containing 2,000 Gold. Grab it before heading down the lift. That gold goes toward weapon and sidearm upgrades, so don't skip it. At the bottom, two long-mouth enemies are waiting. Deal with them, then look for a book sitting on a shelf near the back. Interacting with it reveals a hidden passage into the Forbidden Archives proper.
Mortal Shell 2 Guide: How to Find Grimorium Obscurum in Forbidden Archives
Where is the Grimorium Obscurum?
Once inside the Archives, you'll encounter flying books that periodically launch themselves at you. They deal small amounts of damage individually, but they become a real problem when you're also juggling heavier enemies. Keep moving and don't let them chip away at your health while you're focused elsewhere.
Head toward the middle of the library and you'll find a book holder with an empty slot. This is where the Grimorium Obscurum needs to go, but the book isn't here yet. Look around the area for a jump pad hidden between the bookshelves.
Mortal Shell 2 Guide: How to Find Grimorium Obscurum in Forbidden Archives
Use the jump pad to reach the tops of the shelves. Before going straight for the book, collect the two Ventrium nearby and head toward the chandelier on your left to pick up the Synaptic Vessel. A second jump pad ahead has another Ventrium next to it. From there, drop through an opening in the wall to grab a Glimpse, then return to the jump pad.
The Grimorium Obscurum sits on top of the second shelf from the left, near the chandelier positioned close to the empty book holder. It's visible from the elevated position you reach via the jump pad, but easy to miss from ground level because the shelves all look the same.
How do you use the Grimorium Obscurum?
Drop back down with the book and return to the empty holder in the middle of the library. Place the Grimorium Obscurum in the stand and the path forward opens up, revealing the route to the Ova that needs cleansing.
Mortal Shell 2 Guide: How to Find Grimorium Obscurum in Forbidden Archives
How do you beat the Gloombound Wraith?
Here's the part the dungeon doesn't warn you about. The moment you approach the Ova, a Gloombound Wraith spawns behind you and starts a boss fight. No cutscene, no buildup.
The first phase is straightforward. The Wraith's attacks are slow enough to read, and as long as you're not letting the ambient flying books distract you, you can trade hits comfortably. The fight changes once the boss drops to roughly half health. It glows red and book pages surround it, making it temporarily harder to damage effectively.
At that point, scan the arena for red glowing books and destroy them. Once all of them are gone, the boss reverts to its normal state and you can close out the fight.
What do you get for completing Forbidden Archives?
Defeating the Gloombound Wraith rewards you with two Glimpses and the Curseblood Stone (a Tarstone). Cleansing the Ova completes the dungeon. The Curseblood Stone is a solid pickup for builds that lean into specific infusion paths, so it's worth the detour even if you're not doing the dungeon for main progression.
The full loot breakdown from the dungeon:
- 2,000 Gold (chest at dungeon entrance)
- 2x Ventrium (top of shelves, first jump pad)
- Synaptic Vessel (near chandelier on shelves)
- 1x Ventrium (near second jump pad)
- Glimpse (wall opening past second jump pad)
- 2x Glimpses (Gloombound Wraith reward)
- Curseblood Stone / Tarstone (Gloombound Wraith reward)
If you're building out your resources while working through the Ruins of Mammon, check out the Mortal Shell 2 Gloom farming guide for the fastest ways to level up between dungeons. For players still figuring out which Shell to run, the guide to the best Shells to unlock early covers Tiel, Proxima, and Eredrim with clear reasoning on why each one is worth grabbing first.
For more walkthroughs, boss guides, and item locations across the full game, the complete Mortal Shell II guide collection has everything organized by area and topic.