BG3 Act 2 Guide: 3 Shadow-Cursed Lands Choices That Permanently Lock Companion Quests (and How to Avoid Each)

Verified on BG3 Patch 8 (April 15, 2025). Values reflect the final content patch — Larian has confirmed no further story or mechanic changes.

Act 2 is where most first-time runs break. Not because the combat gets harder — though the shadow curse does — but because three companion questlines contain hidden trigger points that permanently lock based on decisions you’d never guess were consequential. Most guides tell you what happens. This one tells you the exact moment each lock fires and how to avoid it.

If you haven’t finished Act 1, our BG3 Beginner’s Guide covers the Act 1 decisions that feed directly into these Act 2 locks. The Shadow-Cursed Lands also front-load an enormous amount of content into roughly a quarter of the map. It’s easy to sprint toward Moonrise Towers and miss Halsin permanently, or to step through the wrong door without the right companion in your active party. The checklist and player-type table below let you front-load the decisions that matter most.

Quick Start — Act 2 at a Glance

Complete these eight steps in order before engaging Ketheric Thorm:

1. Obtain light protection — Moonlantern or Pixie Blessing — before leaving the safe zone
2. Reach Last Light Inn and speak to Jaheira
3. Defend Isobel during Marcus’s attack — she must survive
4. Wake Art Cullagh at the Inn (requires the Battered Lute from House of Healing)
5. Speak to Halsin and complete the Lift the Shadow Curse portal defense
6. Clear Reithwin Town side content (Waning Moon, House of Healing, Mason’s Guild)
7. Complete the Gauntlet of Shar — with Shadowheart in your active party at all times
8. Infiltrate Moonrise Towers and free the prisoners before the assault begins

The Two Paths Into the Shadow-Cursed Lands

Act 2 begins the moment you cross into the Shadow-Cursed Lands. There are two entry points depending on how you navigated Act 1:

• Mountain Pass route (Rosymorn Monastery Trail): Opens after visiting the Githyanki Crèche or choosing to skip it. This path drops you near the Ruined Battlefield, close to Last Light Inn.
• Underdark route (Grymforge elevator): Comes up beneath the Shadow-Cursed Lands. You emerge near the Road to Baldur’s Gate, slightly further from Last Light Inn but with a Moonlantern within reach if you killed Kar’niss.

The route doesn’t affect Act 2 content, but it affects your starting inventory. If you came through the Underdark and killed the Harpers’ drider escort Kar’niss, you can take his Moonlantern immediately. Mountain Pass players typically need to reach Last Light Inn first to get protection.

Light protection mechanics: The Shadow Curse hits you differently depending on how close you are to Moonrise Towers. Far from the towers, any basic light source (torches, the Light cantrip, Dancing Lights) provides enough protection. Closer to Moonrise, only a Moonlantern or a Pixie Blessing works. A Pixie Blessing — obtained by freeing the pixie trapped inside a Moonlantern — protects your entire party passively and removes the need to carry the lantern at all. Free the pixie as soon as you have a Moonlantern; you don’t lose the lantern’s protection when you do.

Without protection, the game enters automatic Turn Based Mode the moment you step out of a safe zone — you have one turn to find light before necrotic damage begins stacking. In Honour Mode, this can wipe a party that isn’t paying attention.

Last Light Inn — Your First Crisis

Last Light Inn is the Harper and Flaming Fist stronghold in the Shadow-Cursed Lands, kept curse-free by cleric Isobel’s protective ward. Speak to Jaheira here — she’s the Harper commander you’ll need later for the Moonrise assault.

Shortly after you arrive (either immediately or on your next long rest, depending on when you enter), Marcus attacks. He’s a winged True Soul who has come to kidnap Isobel for Ketheric Thorm. This fight is deceptively difficult on first runs because Marcus’s goal is extraction, not killing — he’ll repeatedly target Isobel and use his wings to position her for escape.

How to win the Isobel fight:

• Position melee characters adjacent to Isobel at the start of the fight, not near Marcus. His allies will try to grab her; yours need to intercept.
• Marcus has high mobility with Fly. Don’t waste your first turns chasing him — focus on the lesser enemies dragging Isobel toward the door.
• Crowd control (Hold Person, Hypnotic Pattern, Web) on Marcus’s adds buys turns. Marcus himself is resistant to most debuffs.
• If Isobel reaches 0 HP, her protective ward fails instantly. Every NPC inside the Inn — including Art Cullagh, who you need for Halsin’s recruitment — falls to the shadow curse. Jaheira either succumbs or retreats, and you cannot recruit her later in the same playthrough.

Act 2 has more of these chain effects than any other act — our BG3 Time-Sensitive Quests guide tracks all of them across the full game. The consequence of Isobel’s death cascades across four questlines simultaneously: Halsin’s quest becomes unresolvable, Jaheira’s permanent recruitment is blocked, the Nightsong fight becomes harder, and several quest-givers disappear. Protect Isobel as if she’s the objective of the fight — because she is.

Hidden Decision #3 — Halsin’s Recruitment: The Portal Defense Must Come First

Halsin is the one optional companion whose permanent recruitment requires a specific Act 2 quest chain that most players assume is just flavor content. Here’s the exact sequence:

1. Speak to Halsin at camp after arriving in the Shadow-Cursed Lands. This triggers his quest "Lift the Shadow Curse." Without this conversation, the quest never starts.
2. Wake Art Cullagh at Last Light Inn. He’s the man lying unconscious in the upstairs room. He cannot be woken by normal means — he needs the Battered Lute.
3. Get the Battered Lute from House of Healing in Reithwin Town. It’s in the possession of Malus Thorm. Defeating or bypassing him is covered in the Reithwin section below.
4. Return to Art Cullagh with the lute. He wakes up, gives Halsin the name "Thaniel," and Halsin races to Last Light Inn’s pond.
5. Defend the portal while Halsin retrieves Thaniel from the Shadow Realm. Multiple waves of shadow creatures attack — hold the portal until Halsin returns.

The exact lock: If you defeat Ketheric Thorm without completing the portal defense, the Shadow Curse never lifts, and Halsin does not join your party permanently. He’ll be present at camp but will not recruit as a companion. The portal defense must happen before the Moonrise Towers assault begins — not after.

This isn’t flagged anywhere in the game. Halsin’s camp dialogue doesn’t warn you. Most players discover they’ve locked him out when he refuses to add himself to the party at the end of Act 2.

Reithwin Town and the Thorm Siblings

Reithwin is the cursed town controlled by Ketheric Thorm’s undead family. Three siblings guard key locations, and each can be handled without combat if you read the room correctly.

The Silent Library in the Grand Mausoleum is worth visiting before the Gauntlet of Shar. It’s completely dark and silenced — bring Darkvision or a light source that works in magical silence. The Book of Dead Gods inside completes a puzzle that yields the Spear of Night, which Shadowheart can use if she takes the Shar path. You don’t need the spear to progress, but it’s a significant weapon that you’ll otherwise miss permanently.

Gauntlet of Shar — Hidden Decision #1: The Shadowfell Door

The Gauntlet of Shar is the major dungeon of Act 2 and the climax of Shadowheart’s companion questline. Getting through it requires completing three Umbral Gem trials, defeating Yurgir, and making a permanent decision about the Nightsong. Do all of the following before you enter the Shadowfell:

Umbral Gem trials: Three trials gate the path to the Nightsong. Each Gem requires completing a distinct challenge in the Gauntlet — a precision platforming section with shadows, a faith leap, and combat in the Chamber of Loss. Shadowheart gains +5 approval if she is the one to give blood at the Umbral Altar rather than another companion; this matters for the 50+ approval threshold that affects her parents’ survival in Act 3.

Yurgir: The orthon mercenary is contracted by Shar to guard the Gauntlet. He can be fought, or you can help him break his contract by discovering the Dissonant Whispers method — finding his original contract in the Silent Library reveals a loophole. Siding with Yurgir against his Merregon allies carries risk: it lowers Astarion’s approval significantly, and in some versions of the fight, Astarion may confront you afterward.

Nightsong decision branches:

• Shadowheart kills Aylin (Dark Justiciar path): Shadowheart receives Shar’s blessing, gains Dark Justiciar followers as allies, and acquires the Spear of Night. The catastrophic cost: Isobel’s ward fails retroactively, all Last Light Inn inhabitants fall to the shadow curse, Jaheira either dies or disappears permanently. Shadowheart’s romance is locked out.
• Shadowheart spares Aylin (Selûnite path): Aylin is freed, aids in defeating Ketheric Thorm, and Shadowheart receives the Moonlight Glaive instead of the Spear. She loses Shar’s favor but can access her parents in Act 3. All romance paths remain open.
• Balthazar takes Aylin: This bypasses the immediate confrontation but creates significant Act 3 complications. The game continues but Ketheric Thorm becomes harder to defeat without Aylin’s assistance.

The exact lock — Hidden Decision Point #1:

The Shadowfell door is the gate at the bottom of the Gauntlet that leads to the Nightsong’s prison. The moment you step through it, the game runs a check — not on whether Shadowheart is at camp, but on whether she occupies one of your four active party slots. If she is at camp, even standing right outside the dungeon, the check fails.

What happens: you complete the Nightsong encounter, return through the door, and Shadowheart immediately confronts the party. She has learned you entered the Shadowfell without her — the place where her divine purpose was meant to be fulfilled — and she permanently leaves. The "Daughter of Darkness" quest closes with no resolution, and all its consequences (deity choice, armor, parents, romance) vanish.

How to avoid it: Before you open the Shadowfell door, open your party management screen and confirm Shadowheart is in one of the four active slots. If you’ve been running a different party composition for the Gauntlet, swap her in before the final door. There is no other safeguard.

Moonrise Towers — Infiltrating the Absolute’s Stronghold

Moonrise Towers is the Cult of the Absolute’s headquarters. You can enter through two approaches: infiltration (posing as True Souls or using disguise magic) or direct assault after the Harpers are alerted. The infiltration route gives you access to more of the towers’ interior without triggering full hostility; the assault route is simpler but skips several interior interactions.

Key objectives before the final assault:

• Free the prisoners in the basement: Tiefling refugees and deep gnome prisoners are held in the cells. Free them before the assault begins — the Harper attack on the towers makes the basement inaccessible afterward. The Warden guards the key. The gnomes connect to a separate quest chain that pays off in Act 3.
• Araj Oblodra’s blood donation: Araj is a drow trader in the main hall who offers race-specific potions in exchange for blood. This is a time-sensitive interaction — she flees when the towers come under attack and never returns. Astarion’s confrontation with her (she asks him to bite her) produces a unique scene. The potions she provides vary by race and aren’t available anywhere else.
• Minthara: If Minthara survived Act 1 (she can be non-lethally knocked out rather than killed at the Goblin Camp), she’s imprisoned in the torture room in the basement. Free her here to recruit her permanently in Act 3.

Balthazar’s chambers: On the first floor, Balthazar’s room contains a functional Moonlantern on the central dais and a secret study accessible via the Ancient Altar (requires a heart or severed head from the nearby laboratory). The secret study holds research notes connecting Balthazar to Ketheric’s immortality, and a Shadow Lantern you can craft by combining the Moonlantern with Shadow essence — a useful darkness navigation tool that no other guide highlights clearly.

Throne room judgment scene: The first time you arrive in Moonrise Towers, you’ll witness Ketheric Thorm condemning failed subordinates. How you react in this scene — whether you draw attention to yourself, use illithid powers, or stay silent — affects companion approval and provides intelligence about Ketheric’s weakness (his immortality is tied to the Nightsong).

Defeating Ketheric Thorm — And Hidden Decision #2: Mizora’s Pod

The Ketheric Thorm fight happens in two phases. The first is on the roof of Moonrise Towers after the Harper assault succeeds. The second is in the Mind Flayer Colony beneath the towers — this is where Hidden Decision Point #2 fires.

Phase 1 — Rooftop (Ketheric Thorm): Ketheric starts with a defensive aura tied to his connection to the Nightsong. If you spared Aylin in the Gauntlet of Shar, she arrives and severs this connection, making Ketheric vulnerable and significantly easier. If you killed Aylin or let Balthazar take her, this phase is harder — Ketheric retains his aura for longer. At approximately 25% HP, he retreats into the tower and descends to the Mind Flayer Colony.

The Mind Flayer Colony: Follow Ketheric down into the colony. This is a one-way descent — once you enter the colony, you cannot return to the towers. Explore carefully. The colony contains:

• Brain specimens from the original Nautiloid crash (usable via the Mind-Archive Interface for unique dialogue)
• A path to Ketheric’s final form (the Mind Flayer Phase)
• Mizora’s pod

The exact lock — Hidden Decision Point #2:

Mizora has been imprisoned in a Mind Flayer pod somewhere in the colony — captured by the mind flayers while she was surveilling Wyll in the Shadowlands. Her pod is in a side chamber off the main corridor, not on the direct path to Ketheric. Players focused on ending Act 2 quickly walk straight past it.

If you exit the Mind Flayer Colony without freeing Mizora from her pod, she remains imprisoned permanently. In Act 3, a cutscene fires in which she appears and, furious at Wyll for abandoning her, transforms him into a lemure — a low-ranked devil — as punishment. This is the worst possible ending for Wyll’s storyline and locks out his heroic conclusions. Wyll still functions as a party member after this transformation, but his personal quest resolves to its worst branch.

How to avoid it: Before descending to fight Ketheric’s final form, sweep the colony side chambers. Mizora’s pod requires a DC 5 Perception check to interact with (easy for any character). Once you interact, you can free her. After freeing her, a pact renegotiation dialogue triggers — a DC 14 Persuasion check can modify Wyll’s pact terms, and freeing her grants the Infernal Rapier. There is no signal in-game that this pod exists or that leaving it behind has permanent consequences.

Phase 2 — Mind Flayer form: After finding Mizora’s pod, proceed to Ketheric’s final confrontation. He transforms into a Mind Flayer, and the fight ends Act 2. The party then boards the Githyanki ship for the Act 3 transition.

Before You Leave — Final Act 2 Checklist

Several items and decisions become permanently unavailable once you trigger the Act 3 cutscene. Run through this list before finishing Ketheric:

Jaheira joins automatically after Ketheric falls, provided the Harpers survived the Moonrise assault. She does not require a special recruitment step — she simply asks to travel with the party. If Isobel died and the Last Light Inn fell, Jaheira either died with it or became hostile, and this option is gone.

The Three Companion Quest Locks — Summary

The three permanently-locking decisions covered in this guide, with the exact triggers and avoidance steps:

Frequently Asked Questions

Can you go back to Act 1 areas from Act 2?

Not after entering the Shadow-Cursed Lands. Reaching Act 2 via the Mountain Pass or Underdark closes access to Act 1 locations permanently. Complete all Act 1 objectives — particularly Karlach’s infernal engine repairs, Wyll’s stage 1 quests, and the Goblin Camp resolution — before crossing over.

Is it better to enter Act 2 through the Mountain Pass or Underdark?

Both routes reach the same locations, but they affect your starting gear and certain Act 2 triggers. Mountain Pass: you’ve likely visited the Githyanki Crèche, which advances Lae’zel’s quest and triggers the Voss camp encounter. Underdark: you arrive near a Moonlantern opportunity (Kar’niss) and skip the Crèche, which delays the Voss encounter to Act 3. Neither is objectively better — choose based on whether you want to resolve Lae’zel’s githyanki arc in Act 2 or defer it.

Do you have to kill the Nightsong?

No. Sparing Aylin (the Nightsong) is the better outcome in most runs. She aids the fight against Ketheric Thorm, Shadowheart retains her romance route, and the Last Light Inn survivors remain alive. The only reason to kill the Nightsong is if you specifically want the Dark Justiciar path for Shadowheart or are completing a full evil run.

What builds work best for Act 2?

Act 2 favors builds with reliable crowd control for the Isobel fight and the portal defense, and cold or radiant damage for shadow creatures. Our BG3 Best Builds guide breaks down the top party compositions with Act 2 recommendations included.

Can you recruit both Jaheira and Minthara in the same playthrough?

Yes. Free Minthara from the basement before the Moonrise assault. Jaheira joins automatically after Ketheric’s death. Both are available in Act 3. Note: Minthara requires you to have kept her alive in Act 1 (non-lethal takedown at the Goblin Camp if you sided with the Druids, or simply not killing her if you sided with the Goblins).

What happens if I skip the Gauntlet of Shar entirely?

The game allows you to bypass the Gauntlet and go straight to Moonrise Towers. However, skipping it means Shadowheart’s "Daughter of Darkness" quest never resolves, she doesn’t get her deity choice, and the questline closes permanently when you leave Act 2. Ketheric Thorm is also harder without Aylin’s assistance during the rooftop fight.

Is the Shadow Curse lifted automatically after Ketheric dies?

Only if you completed Halsin’s portal defense quest before the fight. Killing Ketheric without lifting the curse means the curse lifts partially (the region becomes safer) but Halsin’s specific "Lift the Shadow Curse" quest never completes, and he does not permanently join. The distinction matters only for Halsin’s recruitment — the region itself becomes navigable either way.

Sources

• bg3.wiki — Act Two
• bg3.wiki — Shadow-Cursed Lands
• bg3.wiki — Daughter of Darkness (Shadowheart quest)
• bg3.wiki — Mizora
• bg3.wiki — The Githyanki Warrior (Lae’zel quest)
• Game8 — Act 2 Infiltrate Moonrise Towers Walkthrough
• Gamestegy — Act 2 Complete Checklist

Michael R.

I've been playing video games for over 20 years, spanning everything from early PC titles to modern open-world games. I started Switchblade Gaming to publish the kind of accurate, well-researched guides I always wanted to find — built on primary sources, tested in-game, and kept up to date after patches. I currently focus on Minecraft and Pokémon GO.