Elden Ring Shadow of the Erdtree: Thiollier & St Trina NPC quest walkthrough

Thiollier's quest line, which eventually converges with St Trina's, is one of the more complex in Elden Ring's Shadow of the Erdtree DLC. I've laid out everything you need to do in the walkthrough below!

Where to find Thiollier

Thiollier is first found at the Pillar Path Cross Site of Grace in Gravesite Plain. The easiest way to reach here is to head south from the start of Castle Ensis towards the Pillar Path Waypoint Site of Grace.

Then, instead of continuing down the path, turn back around and hug the right side of the cliff until you reach a point where you can drop down. You should be able to see a Miquella Cross on your way there too, which Thiollier is sitting right next to.

Quest walkthrough

Meeting Thiollier

The first step of Thiollier's quest, of course, is meeting the man himself - which can be done by visiting Pillar Path Cross.

You'll want to make sure that you've exhausted his dialogue in this first meeting, but I think even just talking to him once is enough to progress through the quest line.

Getting the black syrup

Following on from your first conversation, you'll then want to talk to Moore - who can be found at the Main Gate Cross Site of Grace just before Belurat.

You might need to speak to him a couple of times or rest at the nearby Site of Grace to get the dialogue to trigger, but he should mention that Thiollier asked him to find some black syrup and that you should deliver it to him.

Returning to Thiollier, you'll want to select the 'Give black syrup' dialogue option, and then 'Ask about the black syrup'. You'll then get the option to select 'I'm weary of life', which results in you getting Thiollier's Concoction. This item isn't actually related to his or St Trina's quest at all, but you'll need it if you want to complete the Dragon Communion Priestess' questline.

Breaking the charm

You might have done this already, but a key part of progressing Thiollier's (and most other NPCs') questline is to reach the point at which Miquella discards his Great Rune and breaks the charm put upon his followers.

If you're unaware, this happens just before you reach the main gate of the Shadow Keep, and a smashing sound should trigger with the message: "Somewhere a Great Rune has broken, and so too a powerful charm."

Once that has happened, make sure to speak to Thiollier again and he'll mention that he's heading to the Southern Shore. Resting at a Site of Grace will trigger this move.

Heading down the Fissure

Once Thiollier has moved, you'll want to head down the Fissure in the Cerulean Coast, which leads to the Stone Coffin Fissure area now that Miquella's seal has been broken.

Progress through this area until you reach the Putrescent Knight boss fight, and make sure to summon Thiollier on the right as you drop into the boss area.

I'm not sure if summoning him is essential to progressing the quest, but you'll likely need the help anyway as this is a very challenging boss!

Meeting St Trina

After beating the Putrescent Knight you'll be able to continue through into the next room and within it will be St Trina - at least in some strange form. Thiollier should also be lying on the ground in the same room, so make sure to speak to him too and exhaust his dialogue.

You'll need to select the 'Imbibe nectar' option when speaking to St Trina four times in order for anything to happen - and don't worry that you keep dying, it's all part of the process.

On the fourth time you imbibe nectar, a cutscene should trigger as you die, where St Trina speaks to you directly.

After this, make sure to speak to Thiollier and select the 'Pass on St Trina's words' option. He doesn't want to hear what you have to say initially, but it seems like if you keep trying the dialogue option a new one should appear stating 'Try to pass on St Trina's words again'.

After triggering this dialogue option, head back to the Site of Grace and rest. You should now be invaded by Thiollier, and defeating him will then reward you with the St Trina's Smile talisman.

After the invasion make sure to rest at the Site of Grace, and then head in to speak to Thiollier. He is now finally willing to listen to what St Trina said to you, but you'll need to imbibe the nectar two more times before you can give him the information he craves.

You'll know that you've reached the final stages of the quest when the cutscene starting with "You must kill [...]" starts, and then you'll finally be able to let Thiollier know what St Trina said. Select the 'Pass on St Trina's words' option, then reset either by resting or imbuing nectar to have the quest reach its penultimate stage.

You should now also be able to summon Thiollier for the second-last and final bosses, making them a bit easier to tackle if you so wish.

Beating the final boss

After you've defeated the final boss, head back to St Trina to find her without a body and withered away. There should be an item in front of her, granting you St Trina's Blossom when you pick it up.

This concludes both Thiollier and St Trina's questlines, and you should also have been able to pick up the former's armour and weapon in the final boss arena after finishing the expansion.