On this page of the Assassin's Creed Valhalla Wrath of the Druids guide, you will find a detailed walkthrough of the Potion of Blood main quest.
Wanting to help Barid, Eivor and Ciara set out to find an antidote for Flann's army.
Reward for completing the quest: 3,400 XP.
- Speak to Barid
- Follow Ciara
- Find and speak to Deidre
- Find and kill The Wren
- Take the amber shard to Deidre
Speak to Barid
Flann's army is poisoned, and the king, believing the words of one of his servants, has accused Barid of treason. Eivor and Ciara promise to find an antidote for the weakened army.
Ciara knows how to help the king's army, but you must find her druid friend, Deirdre. During the journey, you will learn that Ciara once belonged to a druidic group. The woman will also tell you about the Children of Danu cult.
Find and speak to Deidre
When you reach the forest, continue following the path marked by the runestones until you finally reach Deidre's hut. As it turns out, Ciara knew from the start what needed to be done to get the antidote - each of the Children of Danu has a special amber shard that is necessary to create the antidote. Fortunately, Ciara's friend managed to discover the identity of one of the members of the cult. Your task will be to find this person, eliminate them and take the amber.
Find and kill The Wren
Before you can eliminate The Wren, you must first find two clues that will unmask the cultist - mark their position on the world map.
The first clue that will help you figure out where the Wren is hiding can be found in the Auley harbor - see the picture above.
You'll find the first clue in the wooden warehouse on the beach, in the place marked in the image above.
The second clue that will help you figure out where the Wren is hiding can be found in Lough Gara, in the place marked in the picture above.
The second and final clue lies on a wooden crate, in the location shown in the above picture.
Assassinating the Wren
The Wren is hiding in the town of Rathcroghan, in the location marked in the above picture. Be very careful when you enter that town - it is full of hostile guards.
Unmasked members of the Children of Dan cult are marked with a distinctive yellow icon, so you definitely won't confuse them with another target. The Wren can be accompanied by guards - prepare yourself to fight more opponents.
Take the amber shard to Deidre
Return to Deidre and hand her the amber shard. The woman will immediately begin preparing the antidote for Flann's soldiers. During the conversation, you'll learn that the Wren was carrying a note that reveals who is behind the assassination - a person using The Cursed alias. The Potion of Blood quest will end - you will receive 3,400 XP.