Investigate the Selûnite Resistance

This is a walkthrough for the Investigate the Selûnite Resistance sidequest in Baldur's Gate 3. Read on to learn how to unlock the quest, where to find the hidden meeting area in Reithwin Mason's Guild, and the rewards you'll get from finishing the quest!

Side Quest Details

Journal Entry
Investigate the Mason's Guild The Mason's Guild seems to have been the centre of Selûnite resistance in the area. We should seek it out and investigate further.
Recommended Level	Level 6
Rewards	・Helmet of Arcane Acuity ・Moonrise Tower Prison Stash ・Random Scrolls and Potions ・Infernal Iron
Starting Location
Last Light Inn in the Shadow Cursed Lands
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How to Start Investigate the Selûnite Resistance

Read Haldfred's Note in the Last Light Inn Basement

To start the sidequest, you'll need to read Haldfred's Note in the hidden Selûnite Altar located in the basement of the Last Light Inn.

How to Get to the Last Light Inn Basement

Investigate the Selûnite Resistance Walkthrough

	Investigate the Selûnite Resistance
1	Get the Tower-Shaped Key from Mattis
2	Head Southwest from the Last Light Inn
3	Head Down the Ornate Wooden Hatch
4	Open the Keyholed Herald
5	Enter the Hidden Meeting Area
6	Defeat the Shadows
7	Read Mason's Log

Get the Tower-Shaped Key from Mattis

If you helped the Tiefling Refugees in the Emerald Grove, speak to Mattis who is in the main hall of the Last Light Inn and he will mention that Mol gave him a Dusty Key.

You can Persuade or Buy the key for 2000 Gold, which you can further bring down to 1000 Gold. Regardless of your choice, the Dusty Key becomes the Tower-Shaped Key.

Head Southwest from the Last Light Inn

You can reach the Reithwin Mason's Guild by following the path southwest from the Last Light Inn and through the makeshift bridge that brings you to the Reithwin Town Waypoint.

Requires Moonlantern of Pixie's Blessing

The area where the Reithwin Mason's Guild is surrounded by shadow that even the Blessing of Selûne can't protect against.

You'll need full protection, which you can get by obtaining the Moonlantern from Kar'niss and freeing the pixie to get the Pixie's Blessing*.

Seek Protection from the Shadow Curse

Head Down the Ornate Wooden Hatch

Once inside the Reithwin Mason's Guild, go to the western side of main area and climb down the Ornate Wooden Hatch.

Open the Keyholed Herald

Once inside, head to the western side of the room to trigger a Perception Check that will reveal the Keyholed Herald.

Of you got the Tower-Shaped Key from Mattis, simply interact with the Keyholed Herald to reveal the hidden passageway. Otherwise, you may also lockpick the Keyholed Herald to open it.

Enter the Hidden Meeting Area

Follow the passageway south and pass through the doors to enter the hidden Selûnite Meeting Area. Before progressing further, make sure to take a Short Rest or Long Rest as there are enemies you'll need to defeat.

Note: There is a reinforced treasure chest in the hallway leading to the meeting area that you need to disarm and unlock, but the chest is empty so you can just ignore it.

Defeat the Shadows

Head inside the room and you'll be attacked by five Shadows and a Wraith, with the latter emitting an Aura of Oblivion that extinguishes nearby light sources, which will cause the other shadows to disappear in areas with no light.

Prioritize killing the Wraith so that you can use your Torch, Light, Produce Flame, and Dancing Lights spells to illuminate the shadows and make them easier to track.

Note: Volo's Ersatz Eye grants you permanent See Invisibility, which will make it easier to track down the Wraith and Shadows.

How to Get Volo's Ersatz Eye

Read Mason's Log

Once the Wraith and Shadows are defeated, read Mason's Log on the stone dining table to learn more about Ketheric Thorm to complete the sidequest.

Investigate the Selûnite Resistance Rewards

Helmet of Arcane Acuity

You can find a Reinforced Chest in the altar area of the hidden meeting room that contains a Helmet of Arcane Acuity.

This chest requires you to disarm the trap twice to unlock it safely.

Moonrise Towers Prison Stash

Head to the western side of the hidden meeting area and inspect the Moonrise Towers Diagram on the small table. This will unlock a map Hidden Stash icon on your map that directs you to Moonrise Towers.

The hidden stash is located in the cave area leading to the hidden dock where Wulbren and the Tieflings will escape when you help them break out from Moonrise Towers Prison and contains a random amount of gold and arrows.

Rescue the Tieflings (Shadow-Cursed Lands)

Random Scrolls and Potions

Near the table where you find the Moonrise Towers Diagram, pass by the wall for a Perception Check that will reveal a button. Press the button to open a hidden wine cellar and loot the two heavy chests that contain random scrolls and potions.

Infernal Iron

You can find Infernal Iron on a table on the eastern side of Reithwin Mason's Guild.

Note: The Infernal Iron is located in the open area where you find the Ornate Wooden Hatch and not in the hidden area beneath the Mason's Guild.

All Infernal Iron Locations

Lore and Backstory

Reading Mason's Log reveals some lore and backstory regarding Ketheric Thorm, particularly that there is a hidden Sharran Temple underneath the Reithwin Mason's Guild.

This is in fact the Gauntlet of Shar, which is accessible through the Thorm Mausoleum, and is a small hint as to where Ketheric's immortality stems from.

How to Beat the Gauntlet of Shar

Baldur's Gate 3 Related Guides

List of All Side Quests

Prologue Side Quests

Act 1 Side Quests

Druid's Grove Quests

The Risen Road Quests

Blighted Village Quests

Goblin Camp Quests

Nautiloid Crash Region Quests

Underdark Quests

Mountain Pass Quests

This section is currently under construction. Check back later for updates!

Act 2 Side Quests

Last Light Inn Quests

Gauntlet of Shar Quests

Mind Flayer Colony Quests

Act 3 Side Quests

Rivington Quests

Lower City Quests