Baldur's Gate 3: Underdark in BG3 - walkthrough Baldurs Gate 3 guide, walkthrough
Are you looking for a walkthrough of the Underdark in BG3? We explain how to get to Grymforge and how to get to Act 2 of the game - Arcane Tower, Spectator, Bulette.
Last update: 31 May 2024
In this BG3 guide, you will find a complete walkthrough of Underdark. You will discover all possible passages and secrets. You will find out how to complete side quests and the location 100%.
- How to get to Underdark?
- What to pay attention to in Underdark?
- How to advance to Act 2?
- Find the Mushroom Picker
- Help Omeluum investigate the Parasite
- Arcane Tower - how to destroy turrets and run the elevator?
- Arcane Tower - what can you find there?
- Find the Missing Boots
- Cure the Poisoned Gnome
- Defeat the Duergar Intruders
- Selunite Outpost
- Spectator
- Phalar Aluve sword
- Minotaurs
- Bulette
- Festering Cove
How to get to Underdark?
There are 4 paths leading to Underdark. The path you choose has no impact on the further story in Underdark.
One of the passages is located within the Goblin Camp. When you reach the Shattered Sanctum, find the door to the Defiled Temple in the western part of the castle.
Head to the eastern part of the temple and find the room whose interior is illuminated by a beam of light piercing through the ceiling. You don't have to solve the moon puzzle to unlock the door to Underdark. Find the lever on the wall by passing a Perception skill check and unlock it using the Thievs' Tools.
After entering the Underdark, you will get to the Selunite Outpost.
You will find the next entrance in Whispering Depths in the Blighted Village. You'll find the entrance to the Depths in the well in the middle of the village or one of the houses.
Not far from where you will fight the Phase Spider Matriarch is a chasm from which green light is emitted. Bats will fly out of the chasm. You must jump inside to get to Underdark. Just remember to cast the Featherfall spell on all team members first. After landing, you will get to the eastern part of Underground.
The next passage to the Underdark is in the Zhentarim's hideout on the territory of Waukeen's Rest. You will find the entrance to the hideout in the small buildings near the barn with bulls. After you get inside the hideout, we advise not to engage in a fight with the Zhentarims. There is plenty of oil and flammable barrels all over building. Therefore, fighting them can quickly result in the death of the entire team.
Find the sleeping wolf named Istor. Next to him, you'll find a door with an illusion spell imposed on it. Go through the hidden doors. Use the elevator and go down to Underdark. You will find yourself in the north-eastern underground, not far from the Myconid Colony.
The last passage is in Auntie Ethel's Teahouse in the Sunlit Wetlands. On the page Save Mayrina we have described the quest with the witch in details.
When you arrive at her house, extinguish the fire to get to her hideout. Then interact with the door. You will find out that the door is just an illusion. Go through the door and reach the waterfall. Jump to the other side. Not far from the waterfall are the next doors covered with an illusion. Behind them you will find a green portal leading to the southern part of Underdark.
If you cannot get through the door, try putting on the masks found at the first wooden doors.
What to pay attention to in Underdark?
The Underdark is divided into several regions, including 4 Waypoints. When entering the Underdark, your team should be at least level 4. You will encounter many tough enemies and minibosses there.
- Myconid Colony - here, you unlock side quests: Find the Mushroom Picker, Help Omeluum investigate the Parasite, and Defeat the Duergar Intruders. There are 2 merchants in the colony.
- Selunite Outpost - the entrance to the outpost is guarded by two statues. There is a minotaur at the gate.
- Arcane Tower - the entrance to this location is guarded by 2 magical turrets. To thoroughly explore all floors of the tower, you must first fix the broken elevator. You will find here the ingredients needed to complete the side quest: Help Omeluum investigate the Parasite and a lot of loot.
- Beach - here, you will find a ship that will take you to the Grymforge and the Find the Missing Boots quest. In the forge, there is a passage to the Moonrise Towers, which is the beginning of the second act of the game.
- Sussur Tree - here you will find the Sussur Bark, an item associated with the side quest: Forge a Master Weapon.
- The Festering Cove - it's a secret location in Underdark.
The underground is also full of various traps. Equip yourselves with tools to disarm traps, and remember to move carefully. When your character approaches the trap, they will automatically perform a Perception check.
Some traps can be shot down with a regular arrow or a fire ball. You can set fire to the poisonous gas cloud and wait for the danger to be gone.
How to advance to Act 2?
If you want to skip side quests and quickly finish Act 1, go to the beach, defeat the Duergars, and use the ship to get to Grymforge. From there you will be able to use the elevator, which will take you to the Moonrise Towers.
Find the Mushroom Picker
In the colony, you will find a trader named Derryth, who will ask if you have seen her husband. If you answer negatively and ask a few additional questions, you will unlock the quest Find the Mushroom Picker.
Go to the place marked on the map. Upon approaching the cave with green mushrooms, a conversation with Baelen will begin. You can help him in several ways:
- If you have the Misty Step scroll with you, throw it to him performing a Strength check.
- Cast a fly spell on the dwarf.
When Baelen is able to escape from the trap, he will thank you and give you an invisibility scroll in return. Return to Derryth and collect the reward, the Gloves of Uninhibited Kushigo.
Help Omeluum investigate the Parasite
In the Myconid Colony, there is a trader named Blurg. During the conversation with him, tell him about your problem with the tadpole. The merchant will summon the Mind Flyer - Omeluum.
When talking to Omeluum, tell him that you want to get rid of the tadpole. Unlock the quest: Help Omeluum investigate the Parasite. You will have to bring him 2 ingredients that you will find in the Arcane Tower, in the southwestern part of Underdark.
When you return to him with the acquired ingredients, Omeluum will create a potion for you. After drinking, you will be able to pass several ability checks to unlock new Illithid powers. Removing of the tadpole will fail, and the task will be completed.
After drinking the potion, you can buy (or obtain through intimidation) a remarkably useful item from Omeluum called the Ring of Mind-Shielding, which protects against Charm. This ring will be very useful in the fight against Nere in Grymforge.
Arcane Tower - how to destroy turrets and run the elevator?
The Arcane Tower is located in the southwestern part of Underdark. To get inside and examine all its floors, you must first deactivate the turrets and activate the elevator.
The turrets will shoot anyone who tries to approach the door. They can be deactivated in two ways:
- Throw the Sussure Flowers near the turrets, which you can find near the Sussur Tree to the north of the Tower;
- or use any electric spell and inflict enough damage on them.
When the turrets are no longer a threat, you can go to the Tower and start the elevator.
Cast the Fly or Featherfall spell on one of the characters and approach the turret near the statue. Jump on the giant mushrooms at the back of the Tower. Pick up the Sussure Flowers and use the lockpick to open the back door to the Tower.
Approach the generator and put a flower into it. The elevator in the Tower will be unlocked. Go up the stairs to the elevator and go up 2 floors. Open the main door of the Tower and let the rest of the team inside.
Arcane Tower - what can you find there?
On the lowest floor of the Tower, you will find a chest with the Uncovered Mysteries necklace, several books, potion ingredients, and healing potions.
On the first floor of the Tower, you will find Timmask Spores and the Tongue of Madness and ingredients for the Help Omeluum Investigate the Parasite quest.
On the 2nd floor, you will find an Gilded Chest on one of the balconies. When you take all the items out of the chest, you will receive several valuable things, including the Mystra's Grace boots, which provide Featherfall.
On the 3rd floor, you will find a chest with the Mage's Friend ring and many books and scrolls. You will also find a mysterious button by the window. To solve the puzzle with the button, you need to dig up the content of a grave north of the Arcane Tower first. You will find a Dog Collar there. When you put on the collar and press the button, a piece of meat will pop out of the hole.
On this floor, you will also find an Engraved Githyanki Disc on one of the bookshelves. If Lae'zel is in your party, after examining the item, you will unlock a new conversation with her.
On the top floor you will encounter robots. You can defeat them in battle or receive an item from them if you choose the correct dialogue options. You will need 3 books for this conversation:
- Threadbare Book - lies on a shelf on the 1st floor.
- Dusty Book - an open book that lies on the desk on the 2nd floor.
- The Roads to Darkness - it's on the desk on the 3rd floor.
Read all these books, and during the conversation with Bernard, always choose the first possible answer. On the table by the robots, you will find a Guiding Light ring. Put on the ring to discover a button in the elevator that leads to the basement.
Go down to the basement and search all the bookshelves. Don't forget to take the Staff of Arcane Blessing. In the chest, you will find several scrolls, arrows, and the Sparkswall ring.
Find the Missing Boots
You will unlock the Find the Missing Boots quest on the beach in Underdark. As you approach the ships, a Duergar will accost you. Take any ability check, then ask about the boots. Propose help in finding the gnome.
You will find the gnome in the Mykonid colony, she will be lying on a large mushroom. Talk to her and offer help in exchange for boots. When you return with the boots to Duerger, he will let you use the ship, which will take you to Grymforge.
Cure the Poisoned Gnome
In the Mykonid colony, you will find the gnome named Thulla. Give her the antidote to save her from dying. If you don't have an antidote with you, try visiting the nearest trader. Antidote is a very common item in the game.
From Thull you will receive another quest - Save the Grymforge Gnomes. The grateful gnome will give you the Boots of Speed, which the Duergar is looking for by the ships on the shore.
Defeat the Duergar Intruders
In the Mykonid colony, on a large mushroom stands Sovereign Spaw. You will receive a quest from him - Defeat the Duergar Intruders. He will ask you to eliminate the Duergars from Underdark beach.
Go to the beach and attack the dwarves. When the battle starts, more opponents will appear. The strongest enemies will be on the 7th level.
One of the dwarfs will drop the Exterminator's Axe, which deals a lot of damage from poison and fire.
Return to the mushroom colony and speak with the Sovereign Spaw. As a reward, you will receive an Envoy's Amulet, and he will open a secret room for you located in the colony next to the trader Derryth. There will be several scrolls and a Shadow of Menzoberranzan helmet. There are a lot of potion ingredients near Drowa's body, and you will also find the book Flumph Mating Rituals. Read the book and take the ability check to get to know the secret of the forge.
Selunite Outpost
If you got to Underdark through the outpost, wait until the statues at the gate kill the minotaur. If you want to get inside the outpost, you can cast the Fly spell on yourself and try to jump in through the open window.
When you're inside, shoot the stone on the statue which emanates light. The statues at the gate will be deactivated. Next, open the gate with a lockpick and let the rest of the team in.
In the chest by the campfire, you will find the perfect gear for the Paladin, the Helmet of Smiting. In the remaining chests there will be some gold, Thieves' Tools, and tools for disarming traps.
Spectator
Spectator is a boss in BG3, which can be encountered in several ways. It's best, however, to confront him in Underdark, near the Selunite Outpost. Here's how to start a fight with the boss.
Not far from the outpost lies several petrified drows. Attack one of them to awaken the Spectator.
To gain an advantage over the strong opponent, we recommend positioning the team thoughtfully and starting the fight standing on the balcony of the outpost.
Spectator has many powerful attacks and can perform several actions in his turn. If your team is at least level 4, you should quickly deal with him using magical arrows. The defeated opponent will drop the Spectator's Eyes necklace, which has the spells Ray of Fear and Wounding Ray.
Phalar Aluve sword
Between the Selunite Outpost and the Mykonid colony, you will find a sword in the stone. To remove it, you must pass a strength or intelligence check and sacrifice a few drops of your blood. The long sword Phalar Aluve is a finesse weapon dealing 5-14 damage 4 slashing damage.
Minotaurs
In Underdark, you can meet a few Minotaurs. A fight with these beasts shouldn't be too difficult if your team is at least level 4.
If you use the passage to the underground from the Whispering Depths side, you can immediately encounter 2 Minotaurs. During the fight, make sure all characters in your team are not standing too close to each other. Minotaurs can make a long jump and attack several opponents at once.
Bulette
An earthquake? No, it's just another boss in BG3 - Bulette. You may encounter this strange monster between the Whispering Tree and the beach in Underdark.
Bulette can suddenly jump out of the ground and instantly knock down several members of your team. The monster has a sturdy armor and can easily dodge most attacks.
If you want to defeat the boss quickly, position all team members in the four corners of the battlefield so that each character attacks him from a different side. Use the strongest spells, such as Magic Missile and Poison Ray.
The defeated enemy will leave behind the Bloodguzzler Garb, the perfect clothing for a barbarian.
Festering Cove
If you want to discover all the secrets of Underdark, you must visit Festering Cove. You won't find many valuable items there, but you can become a god for a merry bunch of fishfolks!
A hidden path leads to the cove, not far from the place leading to Auntie Ethel's hut. First, shoot all the traps, then jump over the mushrooms to the other side and descend the rock.
A conversation with the inhabitants of the cove can be conducted in several ways. You can fight with them and their 'god' or negotiate with their leader and get the Sickle of BOOOAL from him.
There is also a third, much more enjoyable option - after a successful ability check, you could be claimed as the new god of fishfolks! Sounds good? Here's what needs to be done:
- For this conversation, choose a character with the greatest intelligence and charisma.
- At the beginning of the talk, you have to pass an automatic Nature check.
- Choose the first dialogue option where you accuse their false god.
- Take the chosen ability check for persuasion, strength or intelligence.
- When the illusion disappears, choose the first dialogue option and ask about the power.
- Choose the first dialogue option again and say you will kill him and take the power for yourself.
When you defeat the redcap, the fishfolks will claim your character as their new god. And that's it. Unfortunately, you will not receive any great reward for this, and you also will not find too many valuable items in the bay, except for a few shells and starfish. And fish, of course.
The only thing that might still interest you in the cove is a message in a bottle. Do you remember the little Tiefling that could be saved from the harpies on the beach in Druid Grove? Now you know what the boy was doing there. Doni sent a letter to his father, stating that he hopes to see him in Baldur's Gate.