SoraHoshina
Writer and Editor at - BrandAnime...
Last Updated on January 14, 2026 by SoraHoshina
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Near a lake west of Piramida, Traveler heard a strange recording about “the apocalypse” and entered a mysterious shelter with Paimon.
Curious about the ‘apocalypse’? Head over to the small island west of Piramida to find a bunker and explore the inside to uncover the truth about the ‘apocalypse’ in Genshin Impact.
How to Complete Return to Sender Quest Guide
If you haven’t unlocked the waypoint on the small island west of Piramida, teleport to the waypoint northwest of Piramida and head west to the small island.
Near the waypoint, there is an Ancient Terminal. Interact with it to start the quest and get the Tier 1 Bunker Access Card to enter the bunker (an underground area with another waypoint in it). Go to the lift on your right, and use the elevator to reach the Abandoned Bunker.
Afterward, continue moving forward to the underground waypoint, where you will discover a huge metal door and another Ancient Terminal. Just like before, interact with the terminal to unlock the door.
Inside what looks like the main officer, interact with the Bunker Access Terminal Server, and you will be shown a map of the whole bunker and which floor you have access to. There are three floors in total, and you’re on floor 1.
F2: Research Zone 1
Interact with the map and choose the ‘F2: Research Zone 1’ on the map. This will activate the lift and bring you to the said location. Follow the quest navigation until you reach a room and repair the Purification system (there is a small arrow on top of the valve).
Unfortunately, the system is not working because there is a Rifthound on the other side of the glass, and you need to activate it manually, aka defeating the monster. But you don’t have any weapons with you, so interact with the Ancient Terminal just beside the valve to conveniently kill the enemy, and it will also open the door to your left.
Keep following the quest navigation and use the lift to reach another floor. Use the Rock Enveloped in Kuuvahki and throw it at the objects that were blocking your way.
Once you drop down from the ceiling, take the valve (Spare Bunker Handwheel) from the shelves near the floating terminal, and place it in its rightful place (you can see the small arrow on top of the rods).
Now, you need to enter the experimental site and adjust 4 valves. It’s not marked on the mini-map, but the room is relatively small, so you shouldn’t have too much trouble. But if you still can’t find it after looking around the room, look at the images above for the locations. Note: After adjusting a valve, more Rifthounds will appear, and you need to sneak past them.
After adjusting all 4 valves, immediately get out of the room and activate the Purification system from the terminal once more. This time, you will unlock a Tier II Bunker Access Card for the next section. Return to the main control room – just open the door normally.
On the way, an Evil Eye will spawn in front of the door you need to go through. Take the Spireblooms to create a shield and parry Evil Eye’s attacks. Continue following the quest navigation until the next puzzle.
F2: Research Zone 2
Go back to the main room and enter the door on the left side. Interact with the terminal in the middle first if the door didn’t open.
Once you reach another room via the ceiling, Paimon will mention that there is a gap in the huge glasses. Pick up the Rock enveloped in Kuuvahki and throw it to the pipe on the ceiling (you can see the glowing water there). Doing so will give Kuuvahki energy to the Mandragoras underneath and activate the Nycalyx while also opening the door to your left.
Outside the door, there is one Solaris Core on the left and one Nycalyx right next to Abyss Riftlines. What you need to do is arrange the Mandragoras in order so the Kuuvahki energy can be connected and the Nycalyx can be activated. Continue with the path until you reach a corridor full of Rifthound scratch marks and use the lift.
Continue following the corridor full of scratch marks until you reach the Research Zone 2 and can interact with the terminal to start debugging.
As usual, Rifthound will come at the perfect time to interrupt you, and you need to defeat it. This time, the strategy to defeat it is to lure the Rifthound’s attack so it will hit the cracked pipe that was glowing/leaking Kuuvahki (the attack that has a purple indicator on the ground). Doing so will deal damage to itself.
After two hits, pick up the Rock enveloped in Kuuvahki and aim it at the leaking pipe behind Rifthound to end this battle. Interact with the terminal again, and you will get a Tier III Bunker Access Card.
F3: Supervisory Office
Follow the quest navigation until you return to the main room and when interacting with the terminal, choose the F3 and tap go. Once you reach the floor, look forward and follow along the path to reach the destination.
There is no puzzle here. Right off the bat, you will need to fight with an Evil Eye named Ultimate Calamity. Still, you have no weapons here, so you can only use the following strategy to defeat it.
First, there is a plant on the side that can deploy a strong shield whenever suffused with Kuuvahki. You can take cover there while the Evil Eye is attacking.
While for the offense, take a look around and you will notice 2 plants that can create a shield (one on the left and another on the right side of the room). Behind the plant on the right side, you can see a Spirebloom.
If the Spirebloom is not activated because lack of Kuuvahki energy, pick up the Mandragoras near the shield plant, and throw it to the Spirebloom to activate it. Then you can use it to create a shield and parry Evil Eye’s attacks.
How to parry? Make sure to hold aim to create a shield from the Spirebloom. Then, wait until the Evil Eye’s attacks almost make contact with the shield. You can see that the shield will flash for a bit. Immediately release the hold button to successfully parry. You will get a slow-mo animation if you’re doing it right!
Before the quest ended, you would obtain another Proof of Cognoscenti named Devocina-Cognoscenti’s Sorrow. If you have already obtained the previous Proof of Cognoscenti (Inscripta-Cognoscenti’s Feather, Weavenexa-Cognoscenti’s Intoxication, and Strategema-Cognoscenti’s Mask), you will immediately obtain the quest The Raven Legacy!
How to obtain all the Proof of Cognoscenti Quest Items in Genshin Impact:
➡️ Inscripta-Cognoscenti’s Feather: Complete Whisper Beneath the Waves Quest
➡️ Weavenexa-Cognoscenti’s Intoxication: Complete The Shoemaker’s Children Go Barefoot Quest
➡️ Strategema-Cognoscenti’s Mask: Complete The Tale-Telling Heart Quest
➡️ Devocina-Cognoscenti’s Sorrow: Complete Return to Sender Quest (this quest)
Once you complete this whole quest, you will obtain the “Dead Man’s Hand” achievement in Genshin Impact.
Genshin Impact Quest Guides:
- Genshin Impact: Nod-Krai Valiant Chronicles Complete Guide Version Luna IV
- All New Quests in Luna IV
- Doruud’s Long Poem (When War Songs Rise)
- Return to Sender Quest Guide
- Echoes of a Forsaken Song Quest Guide
- Reverberation of Heroic Spirits Quest Guide
- The Raven Legacy Quest Guide
- A Star Out of Time Quest Chain Guide
- Song of Luscinia / Prelude to the Night Vigil Quest Chain Guide
- To Turn Each Sin Against the Sinner Quest
Genshin Impact Location Guides:
- All Lunoculus Locations in Nod-Krai Luna IV
- Genshin Impact: All Local Legends Location in Nod-Krai Version Luna IV
- Pine Amber Location in Genshin Impact Nod-Krai
- Winter Icelea Location in Genshin Impact Nod-Krai
Sora is a content creator focusing on gacha games in BrandAnime. Aside from playing all the gacha games to a worrying extent, she also streams on her YouTube and Twitch channels (SoraHoshina). If she got bored, then she will write a guide. Yes, write a guide, not anything else that normal people do.
