In Act Two, find the Mason’s Guild on the north-eastern side of Reithwin Town, enter its cellar through the ornate hatch or the upper-floor elevator, then open the concealed passage with the Tower-Shaped Key or a lockpick. To complete Investigate the Selûnite Resistance, defeat the enemies in the Mason’s Hall and read the Mason’s Log on the long stone table.
Spoilers: This guide covers the secret passage, hostile encounters, the resistance’s history, and quest completion.
Find the Mason’s Guild in Reithwin Town
The Mason’s Guild is in the north-eastern part of Reithwin Town in Act Two. You can approach from one of the town’s gates, or cross the ruined bridge from the Ruined Battlefield and enter through the eastern gate. The guild is associated with the Selûnite resistance and the quest Investigate the Selûnite Resistance. bg3.wiki: Mason’s Guild and Reithwin Town are community-maintained references; details such as item placement and encounter triggers may vary with patch version or quest state.
Reach the basement
There are two ways down from the main building:
- Use the hatch: In the far room, interact with the ornate wooden hatch to enter the cellar.
- Use the elevator: Go to the upper floor and operate the control wheel on the balcony to lower the elevator to the cellar.
Open the concealed passage
If you are pursuing the resistance quest, Mattis at the Last Light Inn may give you the Tower-Shaped Key. If Mattis is absent, look for the key in a cobweb-covered pouch behind the Inn’s main bar. The key opens the hidden passage in the guild basement, but it is not essential if you can pick the lock. bg3.wiki: Investigate the Selûnite Resistance
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- In the basement, approach the western wall. A successful DC 10 Perception check reveals the Keyholed Herald.
- Use the Tower-Shaped Key on the keyhole, or pick it with a successful DC 18 Sleight of Hand check.
- Go through the revealed passage and read the threatening note from the Mason.
Handle the basement hazards and fight
The trapped gilded chest
A reinforced gilded chest in the basement is trapped. A successful DC 15 Perception check can reveal the trap; the listed disarm and unlock checks are each DC 14 Sleight of Hand. If the trap triggers, portcullises separate a party member or the party from the rest of the room, and a niche opens to reveal three Gargoyle Statues that fire bolts. The location reference also reports that turn-based mode activates when this happens. bg3.wiki: Mason’s Guild
The Mason’s Hall
Past the trapped section is the Mason’s Hall. According to the location reference, approaching the central table triggers a fight with five Shadows and a Wraith, whether you approach by the middle or the galleries. The encounter trigger and enemy count are source-reported details, not a claim of firsthand testing.
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Complete Investigate the Selûnite Resistance
After the fight, search the long stone table in the Mason’s Hall. Read the Mason’s Log to learn that the mason made a deal with Raphael to eliminate Ketheric’s Dark Justiciars in their stronghold. Reading the log completes Investigate the Selûnite Resistance. The Mason’s Letter to his brother is also on the table. bg3.wiki: Investigate the Selûnite Resistance
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Optional items in and around the Guild
- Main building: Barkskin Recipe.
- Far room: Thieves’ Tools, a Trap Disarm Toolkit, and a Scroll of Burning Hands.
- Backyard: Infernal Iron. If Dammon survived Act One, you can give it to him for rare armor or to advance Karlach’s personal quest.
- Roof and nearby area: Additional loot can be found on the roof and on nearby skeletons.
A plaque beneath the exposed remains in the guildhall reads: “Here lies the Grand Mason, his bones and lies exposed.” bg3.wiki: Mason’s Guild
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