In Baldur's Gate 3, there are plenty of opportunities to play the hero (or be a villain, for that matter.) One early example of this is Mayrina's plight, which players will discover should they travel to the Fetid Bog.
In the first area that players visit in Baldur's Gate 3, there are a ton of secrets to uncover and quests to complete (indeed, this one area made up the entirety of the early access build of the game). This includes the Fetid Bog and Mayrina's quest.
Updated September 6th, 2023: Players that end up skirting close to the Fetid Bog in Baldur's Gate 3 will come across a group looking for someone named Mayrina. If players make their way deeper into the bog itself, they'll find a teahouse and can embark on a journey to save Mayrina from her predicament. Although it sounds simple on paper, saving Mayrina in BG3 is a bit more complicated than simply finding her. To better help players in locating and saving Mayrina in Baldur's Gate 3, the following guide has been updated with a video.
Finding the Fetid Bog
Players wanting to track down Mayrina's quest should first head to the Fetid Bog and meet with her family, who are trying to get her location out of Auntie Ethel. See this guide for information on that dialog and how to find and get across the bog.
Meeting Mayrina
Players will find Mayrina inside the Riverside Teahouse, where Ethel is insisting she eat 'till she bursts. Informing her about the unfortunate death of her family in the Bog will cause her to call off the deal with Ethel, resulting in Ethel teleporting her away. Asking Ethel too many questions about Mayrina will also result in her getting teleported away. Taking Ethel's deal to handle the Illithid Tadpole will also result in Mayrina getting teleported away.
Antagonizing Ethel will trigger a fight with her Redcap allies and cause her to escape through a hidden passage in the fireplace. Players can, after taking out the Redcaps, turn off the fireplace and walk through the back to find their way into her lair. This fight will also be triggered automatically if players discover the secret passage.
Rescuing Mayrina
After entering Ethel's lair, players will need to find a way through the living door blocking the way forward. Wearing one of Ethel's sinister wooden masks can allow someone to see through her illusion here, but this also gives her a chance to take control of whoever wears the mask. A successful wisdom save (aided by being a paladin with "Oath of the Ancients) will allow them to resist it, but it's still best to remove it after heading through the door. Alternatively, players can threaten or otherwise convince the door to tell them how to pass through it, though this will require a successful persuasion or intimidation check.
After passing through the door, players will quickly arrive in an open area, where they will be attacked by some of Ethel's brainwashed thralls. This is a good time to try out the non-lethal attack since they're not in their right minds, but players should be cautious and avoid removing their masks, since doing so will result in their deaths. Beyond this point is a path leading further into Ethel's lair, protected by clouds of poison. These can be briefly cleared by lighting them on fire, but the flames will make it dangerous to move through the area and the gas will return unless players are able to block the vents. These vents can only be seen with a successful perception check and can be blocked by throwing an item on top of them.
After navigating the area with the gas clouds, players will arrive at the area where Mayrina is being kept and will need to fight off Ethel to get her out of this mess. Fighting Ethel can be incredibly difficult, especially if players attempt to do this at lower levels. She can create illusions that can cast spells independently of her and tend to use 
Hold Person
to immobilize the party. She also uses ray of sickness to dish out damage and debuff the party.
Ethel will start the fight by lighting Mayrina's cage on fire, so players will need to head for the control orb on the far side of the room to lower the cage and let her out before it kills her.
Players can tell the real Ethel from the fakes because only the real Ethel can receive debuffs. Using Witchbolt to tag her is also a good way of keeping track of the real one. She'll try switching with Mayrina at some point too, so players should make sure to mark her before that point to avoid accidentally killing Mayrina. After she gets low on health, she'll attempt to bargain with the party to keep Mayrina in exchange for power. Players can succeed an Intimidation check here to get her to give them the power and Mayrina too. (Players will receive an item that grants a permanent +2 to one stat.) Players could also just kill her now, since she has to be very low on health for this dialog to trigger.
After Freeing Mayrina, players should grab the wand "Bitter Divorce" from the next room, and then find Mayrina outside and speak to her near her husband's coffin. Players have the choice of using or destroying the wand, but either way, the quest will now be considered complete and Mayrina will leave for Baldur's Gate. Choosing to use the wand counts as violating the Oath of the Ancients, so Paladins of that Oath should avoid doing so.
Baldur's Gate 3 is available now for PC and Mac, and on September 6th, 2023, for PS5.
