
The Vaults of Forbidden Knowledge in Hell Is Us are concealed passages that offer players exceptional rewards such as defensive gear, unique weapons, and intriguing lore items. These vaults are not only difficult to locate but also require a specific code to unlock.
To reveal the codes necessary for accessing these vaults, players must gather research items and submit them to Tania Alver at the APC. By accumulating sufficient items, you will receive hints about the vault’s location and the corresponding unlock code.
This comprehensive guide will outline each Vault of Forbidden Knowledge’s locations, codes, and the rewards they offer.
Comprehensive List of Vault Locations, Codes, and Rewards

In total, six Vaults of Forbidden Knowledge can be found within the world of Hell Is Us. Each primary area features one vault, with the exception of Talju.
Senedra Forest Vault: Location & Code
The Senedra Forest Vault can be discovered adjacent to the camp where you first find the Medkit for the injured soldier early in the game. If you’re unsure of its location, look for the white X’s on the trees leading uphill from the APC parking spot.
Upon reaching the camp, navigate through the tent and turn sharply right to spot a small crevice in the mountainside. Proceed through this opening to uncover the Vault of Forbidden Knowledge.

The code to unlock the Senedra Forest Vault is: Terror, Admiration, Rage, Amazement.
Rewards from the Senedra Forest Vault

Once the Senedra Forest Vault is opened, players can collect the following rewards:
Reward | Type | Description |
---|---|---|
Glyph – Overwhelm | Glyph | This glyph compels grief energy to form a sphere around you, overwhelming nearby Lymbic Entities and stunning them. |
Glyph – Feed on Fear | Glyph | Create a direct link of fear, siphoning vitality from a terrified Lymbic Entity. |
Letter – To Rosetta | Miscellaneous | In-game lore item. |
Parchment – Preparations | Miscellaneous | In-game lore item. |
Glyph – Wave of Wrath | Glyph | A surge of rage-forward energy damages all Lymbic Entities encountered. |
Glyph – Gluttony | Glyph | A vortex of hyper-desires draws nearby Lymbic Entities into melee range, stunning them upon arrival. |
Amine Prism – Theta | Exploration Item | A tool utilized to seal specific Timeloops. |
Tome – A Bitter Triumph | Miscellaneous | In-game lore item. |
Acasa Marshes Vault: Location & Code
The Acasa Marshes Vault is situated within the locked base camp near Jova. You will acquire the base camp code during the story, but it is available for input at any time. The code for the gate is 151991.
Once through the gate, navigate through the camp and circle around to access a large cave that descends underground. Keep progressing to find the Vault of Forbidden Knowledge.

The unlock code for the Acasa Marshes Vault is: Rage, Ecstasy, Terror, Grief.
Rewards from the Acasa Marshes Vault

The Acasa Marshes Vault is rich in rewards. Below is the list of items you can obtain:
Reward | Type | Description |
---|---|---|
Parchment – Penance | Miscellaneous | In-game lore item. |
Polearm of Terror | Weapon | Guard Protection: 10%, Lymbic Theft: 11%, Parry Agility: C, Attack Speed: B. |
Parchment – A Grand Stratagem | Miscellaneous | In-game lore item. |
Heart of the Griffon | Active Relic | Completes restoration of Health, Stamina, and Lymbic Energy. |
Sword of Grief | Weapon | Guard Protection: 15%, Lymbic Theft: 9%, Parry Agility: B, Attack Speed: C. |
Tuning Stone – Strong | Usable Item | This grants +3, 000 experience points to your weapon. |
Tome – The Endless Horror | Miscellaneous | In-game lore item. |
Tome – Anson Lingen, The Wandering Mason | Miscellaneous | In-game lore item. |
Twin Axes of Ecstasy | Weapon | Guard Protection: 0%, Lymbic Theft: 8%, Parry Agility: A, Attack Speed: A. |
Greatsword of Rage | Weapon | Guard Protection: 20%, Lymbic Theft: 10%, Parry Agility: D, Attack Speed: D. |
Vyssa Hills Vault: Location & Code

The code for unlocking the Vyssa Hills Vault is: Admiration, Amazement, Ecstasy, Rage.
Rewards from the Vyssa Hills Vault
Upon accessing the Vyssa Hills Vault, players can expect the following valuable rewards:
Rewards | Type | Description |
---|---|---|
Glyph – Rapture – Enhanced | Glyph | Surge of energy around you damages all nearby Lymbic Entities. |
Letter – A Spy’s Insight | Miscellaneous | In-game lore item. |
Pendant of Ecstasy – Battle Bliss | Defensive Gear | This item weakens strike-based damage while grievously wounded. |
Parchment – Anticipation | Miscellaneous | In-game lore item. |
Glyph – Animosity – Enhanced | Glyph | A hatred lasso captures a targeted Lymbic Entity, pulling them back into melee range. |
The Unbound Delusion | Passive Relic | This item increases Lymbic Energy but reduces damage taken. |
Glyph – Void – Enhanced | Glyph | A melancholic pool erodes entities within and can be collapsed for increased torment. |
Painting – Lady Marguerith | Miscellaneous | In-game lore item. |
Lake Cynon Vault: Location & Code
The Lake Cynon Vault is positioned on the eastern side of the map. Upon entering the area filled with blue flowers, take a right and continue toward the water to discover an opening in the mountainside. Navigate through the tunnel to locate the vault.
The required code for the Lake Cynon Vault of Forbidden Knowledge is: Vigilance, Grief, Loathing, Ecstasy.
Rewards from the Lake Cynon Vault
Upon unlocking the Lake Cynon Vault, players will receive the following rewards:
Reward | Type | Description |
---|---|---|
Glyph – Perfect Guard – Elite | Glyph | This glyph reduces stamina loss when blocking an attack. |
Tuning Stone – Steady | Usable Item | This grants your weapon +1, 500 experience points. |
Glyph – Lymbic Silvers – Elite | Glyph | This creates multiple shards of ambient Lymbic energy directed at your target. |
Tome – The Ascendance of Hellion Lodges and the Birth of Lymbic Aesthetics, Part 1 | Miscellaneous | In-game lore item. |
Memoria of the Phol | Active Relic | Your weapons gain experience faster due to resonance with past battles. |
Amine Prism – Theta | Exploration Item | This can be utilized to close certain Timeloops. |
Painting – Scion Namir Adam | Miscellaneous | In-game lore item. |
Parchment – A Dire Cost | Miscellaneous | In-game lore item. |
Marastan Vault: Location & Code
The Marastan Vault is accessible by turning the first left from the main road where the APC is stationed. This vault is situated in the southeast area of the map, beyond the large ruins populated by enemies.
After navigating past the ruins, proceed to a small island featuring a rock formation. Enter the opening behind this structure to reach the Vault of Forbidden Knowledge.
The code for the Marastan Vault is: Amazement, Vigilance, Admiration, Loathing.
Rewards from the Marastan Vault
Throughout the Marastan Vault, players will find an array of significant rewards listed below:
Reward | Type | Description |
---|---|---|
Glyph – Frightful Ambush – Elite | Glyph | Creates a pool of terror energy that causes pain to captured Lymbic Entities. |
Painting – Queen Raveta | Miscellaneous | In-game lore item. |
Glyph – Masochistic Delight – Elite | Glyph | You voluntarily inflict damage upon yourself and share the ecstasy with nearby Lymbic Entities. |
Glyph – Waves of Grief – Elite | Glyph | Endless grief energy spills from your weapon, tormenting Lymbic Entities. |
Orison of Valour | Active Relic | Removes all Stamina costs during combat. |
Amine Prism – RHO | Exploration Item | This can be utilized to close certain Timeloops. |
Glyph – Rage Spike – Elite | Glyph | A lance of rage bursts forth from your weapon and detonates upon contact with a target. |
Parchment – Regret | Miscellaneous | In-game lore item. |
Tome – The Ascendance of Hellion Lodges and the Birth of Lymbic Aesthetics, Part 3 | Miscellaneous | In-game lore item. |
Jeljin Vault: Location & Code

The access code for the Vault of Forbidden Knowledge is: Grief, Loathing, Vigilance, Terror.
Rewards from the Jeljin Vault
Last but not least, the Jeljin Vault rewards players with valuable items detailed below:
Reward | Type | Description |
---|---|---|
Chalice of Everflowing Turmoil | Active Relic | Siphon Lymbic Energy from enemies to replenish your own. |
Polearm of Grief | Weapon | Guard Protection: 10%, Lymbic Theft: 16%, Parry Agility: C, Attack Speed: B. |
Sword of Rage | Weapon | Guard Protection: 15%, Lymbic Theft: 13%, Parry Agility: B, Attack Speed: C. |
Parchment – Vanished | Miscellaneous | In-game lore item. |
Twin Axes of Terror | Weapon | Guard Protection: 0%, Lymbic Theft: 12%, Parry Agility: A, Attack Speed: A. |
Greatsword of Ecstasy | Weapon | Guard Protection: 20%, Lymbic Theft: 15%, Parry Agility: D, Attack Speed: D. |
Tome – The Silent Safeguard | Miscellaneous | In-game lore item. |
Tome – The Ascendance of Hellion Lodges and the Birth of Lymbic Aesthetics, Part 2 | Miscellaneous | In-game lore item. |
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