Once you arrive in the Grymforge portion of the Underdark in Baldur's Gate 3, you'll quickly determine that you should find a way to free Nere before you leave. He's another one of the Absolute's True Souls, trapped behind a cave-in and close to inhaling a lethal quantity of poison.
Saving (and then killing) Nere is one of the ways you can acquire a moonlantern to make your way to Moonrise Towers. If you've chatted with the mushroom folks at the Myconid Colony, you can also bring Nere's head to them in return for a reward.
You can totally just wait the entire situation out, letting Nere and the gnomes die together by resting at camp to pass time. When you return, you can loot Nere's corpse for the items detailed below. But if you do plan to dig them out, here are the two best ways to get the materials you need and free Nere.
How to free True Soul Nere by clearing the cave-in
If you plan to proceed with the quest to free Nere, you need explosives to clear the cave-in he and the gnomes are trapped behind. Remember, as your journal warns you, going to your camp to rest will advance time and everyone behind the blockage will die of poison. So you're stuck with however many short rests you have available.
There are two main ways to acquire explosives: one the game points you towards and one that just takes a bit of delving for secrets. Once you have either explosive in hand, right-click it in your inventory, and drop it next to the giant rock pile. After the gnome workers clear the area, light the explosives by shooting them with a Fire Bolt spell or tossing a lit torch.
How to get explosives easily
If you just want the quick combustible option, there are two smokepowder satchels hidden behind a secret door elsewhere in the Grymforge. Find the unguarded, unlocked metal door east of the docks on the lowest level of Grymforge. It's just below the big wrought-iron gate leading to the elevator that will eventually take you to Moonrise Towers.
- Walk through the metal door to the end of the dark hallway
- If you succeed at a passive Perception check, hit the button on the right side wall to open a secret door
- Alternatively, there is a collapsed archway if you have abilities for travelling through tiny spaces
- Pick up the smokepowder satchels sitting on top of the rubble behind the treasure chest
Where to find Philomeen's runepowder
If you ask around the Abandoned Refuge area, you'll hear that one of the gnome workers recently ran off with some explosive runepowder. You can find Philomeen and acquire some (or all) of it, to free Nere. There are two routes to find Philomeen:
- Get through the locked double iron doors east of the docks in Grymforge by convincing Brathwen and Viss to leave and then lockpicking your way in
- Jump down from the upper level, accessed by the catwalks above Grymforge
Convincing Brathwen and Viss to abandon their grim duty of tossing dead gnomes in the water isn't too difficult—there are just a couple skill checks involved. Once inside, head to the left through a secret door (accessed by a button on the wall) and up a set of stairs past three ochre jellies. You can sneak through the area if you don't want a fight.
If you happen to have cleared the rubble on the north end of Grymforge with the help of the rothe, you can access the path to Philomeen a different way. Jump down from the upper floor at map location X:-600,Y:410. This won't get you out of doing the ochre jelly fight, though.
You'll find Philomeen behind a locked intricate door and need to either fight her to obtain the entire barrel of runepowder or talk her into giving you a vial. It's easiest to talk her down if you've already spoken to the other gnomes so you can namedrop Laridda for a difficulty class 10 persuasion check. The other options are DC 15 checks for persuasion and intimidation.
Should you save or kill Nere?
After you've freed Nere from the cave-in, you'll enter a conversation where you either side with him or the duergar rebels. You should kill Nere to get two sets of loot rewards, unless you're going for an evil run and want to save him for roleplay reasons. He's a real bad guy though, murdering and abusing enslaved gnomes, so you can find all the righteous reasons you need to slay him and take his goodies.
When you loot Nere you get:
- Dagger +1
- Sword of Screams (adds 1d4 psychic damage)
- Disintegrating Night Walkers (grants the misty step spell)
- Broken moonlantern
- Another mind flayer parasite
If you bring Nere's head to Sovereign Spaw at the Myconid Colony you get:
- Envoy's Amulet (grants Voice of the Circle class action to grant an ally +2 on Persuasion checks)
How to fight Nere
Fighting Nere is considerably easier if you've made a deal with Elder Brithvar to betray him. The duergar and one of his guards are plotting on a balcony just north of the room with the cave-in. If you speak with him ahead of time and agree to kill Nere after freeing him, Brithvar and five other guards will join the fight as your allies.
With all that help on your side, killing Nere and his Absolute novices isn't too difficult. Be wary that Nere and Mind Master Dunnol both have the ability to turn your own allies hostile. And do mind the lava pools in the room as well. Enemies will attempt to shove or cast thunderwave to knock you and your friends in, so turn that strategy against them first if you can. A warlock's eldritch blast with the invocation that adds pushback can be particularly useful, but a good old bonus action shove does the job too.