ESO Nowhere Vault Arcanum Wing Puzzle: All Rooms and Secret Route

The ESO Nowhere Vault Arcanum Wing Puzzle contains four rooms: Hunt of the Watchers, Murky Grotto, Fungal Chasm and Custodian’s Repository. Three are challenge rooms, while Custodian’s Repository is the wing’s safe room. Completing them is straightforward once you understand their objectives, but finding every secret requires several hidden interactions.

The Arcanum Wing also connects to the other two wings of the Nowhere Vault. You’ll need Watcher Filtration Gills, Fungal Sight and Subjugating Mindspore to progress through its secrets, while Astralight Lumen from Lunar Path unlocks another seal. These items form part of the route towards the Ancient Direnni Quasigriff mount.

ESO Nowhere Vault Arcanum Wing Puzzle: All Four Rooms

Image credit: ZeniMax Online Studios

The Arcanum Wing contains the following rooms and hidden rewards:

Room	Secret reward or objective
Hunt of the Watchers	Watcher Filtration Gills
Murky Grotto	Fungal Sight
Fungal Chasm	Subjugating Mindspore
Custodian’s Repository	Lunar Path Timeward Seal, using Astralight Lumen

The ESO Nowhere Vault Arcanum Wing Puzzle follows a fixed sequence of secret prerequisites, even though room selection can vary between runs. Hunt of the Watchers starts the chain, and Fungal Chasm provides the item needed to unlock the Arcanum seal in Cursed Castle.

Hunt of the Watchers: How to Get Watcher Filtration Gills

The first stage of the ESO Nowhere Vault Arcanum Wing Puzzle takes place in Hunt of the Watchers. The normal objective requires collecting five Seeker Glyph Keys and using them to unlock the sealed area.

Once you’ve completed that objective, stay in the room. Leaving immediately means missing the hidden Watcher encounter.

To collect the Watcher Filtration Gills:

1. Find the Shrill Whistle resting on one of the hills.
2. Locate the remaining Watcher with a green symbol above its head.
3. Lure the marked Watcher towards the Runic Prison near the starting area.
4. Bring it close to the green sigil and use the whistle and prison interaction to remove its immunity.
5. Defeat the vulnerable Watcher and collect the Watcher Filtration Gills.

Finishing the normal room objective first removes the other Watchers, making the marked enemy easier to identify and lure.

The Watcher Filtration Gills are required for the next secret encounter in Murky Grotto. If the marked Watcher remains immune, check its position at the Runic Prison rather than continuing to attack it.

Murky Grotto: How to Spawn Toxic Matron

Murky Grotto is an endurance encounter with a hidden boss. The secret requires keeping the wave event active instead of defeating everything as quickly as possible.

Enter with the Watcher Filtration Gills obtained from Hunt of the Watchers. Live player testing has confirmed that the gills are needed to trigger the hidden encounter.

To complete the Murky Grotto secret:

1. Activate the Toxic Bud to begin the encounter.
2. Stay close to the activated plant and survive the incoming poison damage.
3. Avoid killing the toxic plants or eliminating every enemy in the waves.
4. Remain inside the damaging area that appears during the encounter, using healing to stay alive.
5. Continue surviving until the Toxic Matron spawns.
6. Defeat the Toxic Matron to receive Fungal Sight.

The encounter can end before the secret boss appears if you clear the enemies too quickly. Prioritise survival and healing while waiting for the Toxic Matron.

Fungal Sight is the next required effect in the ESO Nowhere Vault Arcanum Wing Puzzle. The in-game achievement uses this name, although some early community guides call it Fungal Vision.

Fungal Chasm: Hidden Staircase and Subjugating Mindspore

Fungal Chasm combines platforming with a hidden path that only becomes visible after obtaining Fungal Sight.

The normal room involves navigating across dangerous platforms and mushroom-filled obstacles. Its separate secret leads to the Subjugating Mindspore.

Once you have Fungal Sight:

1. Enter Fungal Chasm and look towards the left side of the room from the entrance.
2. Find the translucent green staircase revealed by Fungal Sight.
3. Jump onto the first section and follow the green steps upwards.
4. Continue into the concealed upper area.
5. Interact with the Subjugating Mindspore to collect it.

The staircase is faint and can be difficult to spot against the surrounding environment. Returning towards the entrance provides a clearer view of its starting position.

Sorcerer’s Streak ability can help with the awkward jumps, but it isn’t required to unlock the staircase. The essential prerequisite is Fungal Sight.

Collecting Subjugating Mindspore completes the third secret effect in the ESO Nowhere Vault Arcanum Wing Puzzle. You’ll use it later in Prison of the Unrepentant, located in Cursed Castle.

Custodian’s Repository: Astralight Lumen and the Seal

Custodian’s Repository is the Arcanum Wing’s safe room. Its hidden interaction belongs to a different secret chain, which begins in Lunar Path.

You must obtain Astralight Lumen before the seal can be collected.

Astralight Lumen comes from three Lunar Path rooms:

1. Moonlit Isles: Solve the secret bridge puzzle and collect the Resonating Core.
2. Twilight Maze: Follow Little Soft Boots through the hidden route and use the Resonating Core to obtain Cantor’s Starsong.
3. Eclipsed Hall: Complete the lantern objective, collect the mallet near the exit, ring the central bell and then ring the bells that turn blue to obtain Astralight Lumen.

With Astralight Lumen available, enter Custodian’s Repository and look for the Astral Tear on the right side.

Interact with the Astral Tear to collect the Timeward Seal associated with the Lunar Path secret chain.

This completes the Lunar Path seal collection, even though the final interaction takes place inside Arcanum. The Arcanum Wing’s own secret chain ends elsewhere.

ESO Nowhere Vault Arcanum Wing Puzzle: Full Secret Route

The Arcanum Wing’s hidden items eventually lead to Prison of the Unrepentant in Cursed Castle.

To finish the ESO Nowhere Vault Arcanum Wing Puzzle secret chain, follow this order:

1. Collect Watcher Filtration Gills from Hunt of the Watchers.
2. Use the gills to access the Toxic Matron secret in Murky Grotto.
3. Defeat Toxic Matron to receive Fungal Sight.
4. Use Fungal Sight to reveal the hidden staircase in Fungal Chasm.
5. Collect Subjugating Mindspore at the end of the staircase.
6. Enter Prison of the Unrepentant in Cursed Castle.
7. Find the Physical Escape interaction in one of the side rooms.
8. Use Subjugating Mindspore to activate the secret and obtain the Arcanum Timeward Seal.
9. Return to the Sage’s Trove and use the seal on its corresponding barrier.

The Arcanum chain is also associated with the A Cage That Shines Rumor. Breaking its corresponding seal awards five Wondrous Nowhere Keys.

The other wing chains follow a similar pattern. Lunar Path provides Astralight Lumen for Custodian’s Repository, while Cursed Castle provides Connoisseur’s Vision for The Lakehouse in Lunar Path.

Once all three seals have been obtained and the final barrier dispelled, the Heir to the Sage’s Legacy achievement awards the Ancient Direnni Quasigriff mount.

ESO Nowhere Vault Arcanum Wing Puzzle Achievements

Completing the Arcanum Wing contributes to two separate achievements.

Arcanum Inquirer requires completing the three challenge rooms and visiting Custodian’s Repository. You don’t need to finish every hidden secret to meet the room-completion objective.

Mysterious Revelations requires obtaining the following four secret effects:

• Watcher Filtration Gills
• Fungal Sight
• Subjugating Mindspore
• Arcanum Timeward Seal

The Arcanum Timeward Seal is obtained through the Prison of the Unrepentant interaction using Subjugating Mindspore.

Players pursuing the Ancient Direnni Quasigriff must also complete the Lunar Path and Cursed Castle seal objectives before dispelling the barrier.

ESO Nowhere Vault Arcanum Wing Puzzle Not Working?

The most common problems involve missing prerequisites or ending a room’s normal encounter before its hidden objective is complete.

Watcher remains immune: Return to the Runic Prison near the beginning of Hunt of the Watchers. Make sure you’re targeting the Watcher with the green symbol and have collected the Shrill Whistle.

Toxic Matron doesn’t spawn: Confirm that you’ve obtained Watcher Filtration Gills. Keep the Murky Grotto wave encounter active, avoid killing the toxic plants and survive the poison damage until the hidden boss appears.

Green staircase doesn’t appear: Fungal Sight must be obtained from Toxic Matron before the hidden route becomes visible. Look towards the left side of Fungal Chasm from its entrance.

Astral Tear cannot be activated: Custodian’s Repository requires Astralight Lumen from Eclipsed Hall. Completing the Arcanum challenges alone won’t unlock that interaction.

Nowhere Vault room selection can require multiple visits, so you may encounter a destination before obtaining its prerequisite. Secret progression carries across runs, allowing you to return when the required room appears.

The ESO Nowhere Vault Arcanum Wing Puzzle is complete once you’ve cleared its four rooms and collected the Arcanum secret effects, including the seal obtained in Prison of the Unrepentant. With those objectives finished, you’ll have completed Arcanum’s contribution towards unlocking the Ancient Direnni Quasigriff.

Official source: ZeniMax Online Studios, Update 51 Live Patch Notes.

Official source: ZeniMax Online Studios Update 51 launch issues report and the official ESO Update 51 patch documentation.