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Baldur’s Gate 3: How to Beat Marcus & Save Isobel

Sometimes even saviors need to be saved. This is the case with Isobel, the savior of Last Light Inn. A cleric of Selȗne, Isobel is the only thing keeping the Last Light Inn and its survivors safe from the Shadow Curse corrupting the lands. Naturally, that makes her a target for the darker forces at play. If you’ve reached Act 2 and find keeping Isobel safe a challenge, then have no fear. In this Baldur’s Gate 3 guide, we’ll be going over the best way to beat Marcus and save Isobel during the attack on the Last Light Inn.

Spoiler Warning

If you haven’t already realized, this guide will have spoilers for a fair bit of Act 2 and the fates of several characters. If you just want to know how to save Isobel then jump to the tactics section below to skip some of the spoilers. And with that let’s get into it!

Finding Isobel

Isobel preparing to shield the inn. - How to Beat Marcus & Save Isobel in Baldur's Gate 3
Image: Larian Studios via HGG / Justin Moniquette

When going into Act 2, there are two ways to get to Isobel. Depending on how you handled the Emerald Grove and the Tieflings, will determine the options for your path. Before we go into the tactics of the fight, we’ll go over how to find our cleric in distress.

Through the Underdark

If you couldn’t bring yourself to exterminate the Grove and side with Minthara, then you have to take the long way to Last Light. Once you’re ready to move on from Act 1 and see the Tieflings off from the Grove, make your way to the Underdark.

At this point, you should have a couple of entrances to choose from. Through the Shattered Sanctum in the Goblin Camp, the Hag’s Lair, and the Zhentarim for example.

After going through the Underdark and riding the elevator up from the Grymforge, the area after the Underdark, you’ll find yourself in the Shadow Cursed Lands. Eventually, you’ll meet up with the Harpers. Work with them, and you’ll be taken directly to the Last Light Inn and Isobel.

Through the Mountain Pass

Your other option to get to the Shadow Cursed Lands, and the Last Light Inn, is through the Mountain Pass. If you sided against the Grove and worked with Minthara, then you’ll be given a special lute that lets you summon Kar’niss, a drider working for the Absolute.

Take this route and he’ll take you directly to Moonrise Tower. Halfway through the journey, you’ll be waylaid by some Harpers. 

At this point, you have a choice. You can side with the Harpers, who will take you directly to Last Light Inn, or you can continue to work with the Kar’niss and the Absolute. While siding with the Harpers takes you directly to Last Light, which is the goal, you could continue to Moonrise Tower and make your way to the inn later. Either way, you have a fight on your hands.

Fighting Marcus & Saving Isobel

Once you make your way to the inn, you can find Isobel on the upper floors. But BEFORE you approach her room, save your game. The fight to save/protect Isobel will begin immediately after you finish speaking with her, and you don’t want to be stuck in an unwinnable situation.

Upon speaking with her, you’ll find out that Isobel is a cleric of Selȗne and is using her power to protect the inn from the Shadow Curse and its influence.

It’s made clear that without Isobel and her shield, the inn will fall to the Shadow Curse, and everyone inside will die or worse. If you sided with the Tieflings, then this might make saving Isobel especially important, as you’ll see some familiar faces holed up here as well.

Eventually, you’ll be interrupted by Flaming Fist Marcus, a traitor sent to retrieve Isobel for the Absolute. He comes with a pack of Winged Horrors and tends to be a massive problem for most unprepared players.

Moments before the fight - How to Beat Marcus & Save Isobel in Baldur's Gate 3
Image: Larian Studios via HGG / Justin Moniquette

Who you bring will change the difficulty of this fight drastically. Simply winning the fight won’t keep Isobel safe, you also need to keep her alive. If Isobel’s health drops to 0 at any point, she will be taken away by Marcus, and you will have failed to protect her.

My recommendations for your party are Shadowheart, Wyll, and any frontline of your choosing. I brought Karlach to act as a meat shield for Isobel and dish out some damage, and she did perfectly. Your 4th party member is up to you, though we suggest bringing either more damage or CC.

The real MVP of this fight is going to be Shadowheart. Her ability to heal and her AoE spells will be key in keeping this fight under control. Load her up with spells like Spirit Guardian, Sanctuary, Healing Word, and Mass Healing Word.

Spirit Guardian will provide excellent AoE damage if you choose the radiant damage type. Especially in the small room the fight starts in. Sanctuary can be used on Isobel to keep her safe for a round or two. Healing Word and Mass Healing Word are pretty self-explanatory. The ability to heal using a bonus action frees Shadowheart to make the most out of her turn.

Because of the close quarters, I chose to bring Wyll over Gale. With Pact of the Blade, he acts as a pretty good gish, able to sling spells and use a sword if needed. Give him Cloud of Daggers to lock down choke points and Fireball if you can find the proper angle to use it without taking out your team. Other than that, have him use Hex on Marcus and wail on him, since he’s the biggest target.

Karlach’s role in this fight is pretty simple. Have her hit anything she can get her hands on. Depending on what type of character you’re running, she can either act as the main damage dealer against Marcus or as clean-up crew for the Winged Horrors that surround you. 


Marcus Fight - Baldur's Gate 3
Image: Larian Studios via HGG / Jeffrey Hsu

This fight may seem overwhelming at first, especially when trying to keep Isobel alive. But if you go in with a plan, it’s not too bad. That being said, any plan can be ruined by a bad roll of the dice, so don’t hesitate to reload your save if things go abysmally.


To begin with, try to position your party members by the doorways to block the Winged Horrors from entering the room. At the very least, you’ll want to prevent them from easily reaching Isobel, as all enemies are coded to focus their attacks on her.

Given that Isobel is rather fragile (with only 11 AC and 52 HP), it’s completely possible for her to go down before you can even act if your party rolls a low initiative.

You should also preemptively apply any buffs that you have available to your party before speaking with Isobel and triggering the fight. Luckily, conversations freeze the timer on buffs, so you won’t have to worry about them expiring.

If you have access to Grease, you can even apply it to the areas where the Winged Horrors will enter the room from to hopefully knock them prone once the fight starts.

Target Priority

The main thing you want to do is get Flaming Fist Marcus out of the fight as soon as possible. He will hit harder than any of the Winged Horrors and will solely focus on Isobel unless he has no way to reach her.

The Winged Horrors aren’t particularly tough, but action economy is king here. Just don’t let them reach Isobel, and you can whittle them down fairly quickly. If you absolutely can’t prevent them from getting past you, at least position yourself to get attacks of opportunity on them.

Naturally, you’ll have to also keep an eye out on Isobel’s health. If she begins to get dangerously low, you may have to prioritize healing her and hoping the enemy misses their next attack. Though given her low AC, that’s not an ideal case – unless you spent a turn applying buffs to her.


As I mentioned earlier, have Karlach focus on Marcus or the Winged Horrors, so they don’t swarm Isobel. Use Shadowheart to provide heals and buffs as necessary. You want to keep Spirit Guardian active as much as possible, since it provides an excellent source of damage.

Use Wyll to lockdown choke points for any Winged Horrors that join the fight later and send him to Marcus whenever you can. If you have access to Hold Monster, you can attempt to render Marcus completely helpless for 10 turns.

Emergency Options

If things are going poorly or you’re still struggling, you can also opt to just pull Isobel out of the fight.

Casting Invisibility on Isobel will throw your enemies into a state of confused anger, as they’ll turn to focus on your party before searching for her. However, Isobel has the rather bad habit of breaking Invisibility on her next turn with some sort of action. That being said, it might buy you enough time to reposition and take control of the fight again.

Alternatively, if you have access to Dimension Door, you can straight up teleport Isobel away from the area (and out of immediate danger). This will pull one of your party members out of the fight, but if your only concern was keeping Isobel alive, you can proceed to go all out on killing Marcus and his minions.

Useful Items & Equipment

If you save Isobel, she'll successfully put up the shield around the Last Light Inn.
Image: Larian Studios via HGG / Justin Moniquette

While technically not necessary to win this fight, there are a couple of items that do make saving Isobel a lot easier. Funny enough, most of these items are going to Shadowheart. The irony of a Cleric of Shar being a key component of saving a Cleric of Selȗne is not lost on me.

The first and most important item is The Blood of Lathander. A legendary mace housing the blood of a god, The Blood of Lathander has a lot of benefits that trivialize this fight. The main one is the ability to blind any undead in a 6m radius. This can potentially shut most of the Winged Horrors in the fight meaning you can focus all your efforts on Marcus. This mace can be found under the Gith Creche in the Mountain Pass.

The second item is the Boots of Aid and Comfort. These boots give an additional 3 temporary hit points whenever the wearer heals a target. It’s not a lot, but any overhealth on Isobel can save her life. These can be bought from Grat the Trader in the Goblin Camp in Act 1.

The third item is the Hellrider’s Pride. These gauntlets give a target resistance from weapon attacks when they are healed. This can greatly reduce any damage coming Isobel’s way and give you more breathing room during the fight. These can be obtained from Zevlor, either by robbing him or stopping Kagha’s ritual.

The last item is The Whispering Promise. This ring gives the target of a heal a +1d4 bonus to Attack Rolls and Saving Throws for two turns. Just like the previous two items, these help in keeping Isobel alive. This item can also be bought by Grat the Trader in the Goblin Camp.

Join the High Ground!

And that’s our guide on how to beat Marcus and save Isobel in Baldur’s Gate 3. Have you attempted this fight yet? Have you saved Isobel? Let us know in the comments below how you did it. And for more content like this in the future don’t forget to subscribe.

Happy Adventuring!


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