The Great Vault Mission Walkthrough in Borderlands 3

Borderlands 3 The Great Vault Mission

The time has come to fight back against the Children Of The Vault but the Calypso twins have something planned already and it is up to you to stop them from pulling through with their plan.

Your task is to continue the assault that failed previously but this time with Tannis using the Eridian amplifier, you will be able to penetrate their base and fight the Calypsos head on.

Mission Walkthrough

Call From The Calypso Twins


Speak to Lilith once you have finished the Angels And Speed Demons mission, head to Lilith and speak with her to plan out the next move.


Lilith will be interrupted by an incoming message from the Calypsos telling the Crimson Raiders to take a look outside the window.


A bright beam will fire from pandora to the moon which later on reveals that that Troy Calypso is actually charging it as it happens to be the vault key to The Great Vault.

Saying Your Goodbyes


The time has finally come for you to face the Calypsos and Lilith tells you to say your goodbyes to the crew before heading out.


It is optional to talk to all of the crew members listed in the objectives or you can talk straight to Lilith to begin heading out.

Attacking The Children Of The Vault


Head to Roland’s Rest and speak with Vaughn to begin the assault against the Children Of The Vault.


Tannis will use the Eridian amplifier to power herself up and will head over near the turrets which prevented the previous attack of the Crimson Raiders.


Grab a vehicle and head over to where Tannis will be waiting near the turrets so you can back her up as she takes control of them.


Exit your vehicle and head over to Tannis but you will have to clear the Children Of The Vault in the area before meeting up with her.


Head up the stairs and proceed towards the waypoint and kill all of the Children Of The Vault that are in the way.


There will be several enemies to kill before reaching Tannis so make sure you take them all out in order to proceed to her location.


Head towards Tannis and she will take control of the turrets guarding the Children Of The Vault, turning them to the side of the Crimson Raiders.


Get back into your vehicle and proceed with the attack against the Children Of The Vault by heading to the waypoint.


The next zone will be accessible and you are to head inside along with your vehicle where you will then drive to the location where the Calypso twins are charging up the vault key from afar.


Drive your way through the enemy defenses and make your way towards the waypoint marked on your map.


Once you reach the waypoint, dismount your vehicle and follow Ava who has joined in on the assault against the Children Of The Vault.


Wait for Ava to place a bomb at the entry point so you can shoot it to make an opening for the Crimson Raiders to enter.


Once the bomb is in place and Ava has moved out of the way, shoot the bomb and charge in to kill the Children Of The Vault inside.


You are then to clear out all the Children Of The Vault in the area before you can proceed further into the base.


Leave no enemy standing and make your way towards the Courtyard Of The Damned after killing every last bandit in the area.


After clearing the enemies continue making your way towards the waypoint until you reach the Inner Sanctum.

Entering The Inner Sanctum


Head towards the waypoint where you will later on need to open up the path going further into the Inner Sanctum.


You will find a lever which will open the sanctum door and must use it in order to proceed heading towards Troy and Tyreen.

Cutting The Eridian Supply


There will be tons of Eridian being processed in the Altar Of The Twins which you will need to sabotage in order to prevent Troy from gaining more Eridian to power himself with.


You will first need to kill Rachael, The Anointed who is standing guard at the Altar Of The Twins in order to carry out the sabotage of the Eridian supply.


Once the anointed enemy has been killed, make your way to all four valves which you will interact with to raise the pressure of the tank where the Eridian is being supplied.


Once all the valves have been accessed, the pressure will be too much to handle and the tank will become unstable, allowing you to shoot at it and eventually cause it to explode.

Heading To The Great Vault


Once the supply of Eridian has been cut off, head down the hole marked by a waypoint and jump down to head to where Troy and Tyreen are located.


A zone called The Great Vault will be accessible and you will then head inside to face Troy and Tyreen.


You will be in a dig site and will need to head over to the waypoint but be sure to restock on ammunition as you will be up for a big fight.


Head towards the waypoint which marks the entrance to the area where Troy and Tyreen are charging the moon from.

Fighting Troy Calypso


Once you reach the waypoint, jump down and a you will then need to fight Troy while Tyreen is busy channeling her siren powers.


Troy will attack you using his siren abilities and you will have to fight back with whatever you have on you if you decided to proceed without preparing.


Fight Troy until you completely deplete all of his health which will end with a cutscene of him and Tyreen dropping to the ground.


Troy will be dead and Tyreen will be able to get up where she then absorbs Troy to make a final attempt to attack which is successful, allowing her to escape.

Call From The First Vault Hunter


An echo device will be left behind and you will need to pick it up to check who it belongs to and respond to a call.

The call is from Typhon DeLeon who tells you that the great vault is about to open and that you need to head over to Nekrotafeyo as soon as possible.


After Typhon DeLeon’s call about heading to Nekrotafeyo, head over to Lilith and speak with her to proceed with the mission.

Looting The Great Vault


Before setting out to Nekrotafeyo, you will enter the vault which has just opened in the area and loot what you can.


Head over to the Eridian Analyzer which is stored within the vault and take it followed by looting anything else you can inside the vault before heading back to Tannis.


Head outside and speak to Tannis in order to complete the mission as well as make the next main mission active.

The Great Vault Mission Rewards


Upon completion of The Great Vault you will receive a reward of around 11,314 cash and a rare head costume item.



  • There will be a huge fight ahead of you heading through the whole base along with facing Troy at the end so be sure to prepare all your gear before heading out.
  • While in your vehicle, you can simply rush towards the waypoint to avoid wasting time with the enemy defenses.
  • Troy will attack with easy to analyze patterns which can help you avoid taking unnecessary damage and later on end his life easily.

Other Main Missions Walkthrough

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Michael James

Michael James has been an avid gamer since he was young. He loves to play video games and enjoys writing about it to share his experience and ideas with others. Aside from playing, he also enjoys helping other gamers both ingame and on-site.

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