Potion of Blood is a main quest in the new DLC of Assassin’s Creed Valhalla.
Your task is to kill The Wren and get the cure for the poisoned soldiers.
Here’s a walkthrough of Potion of Blood in AC Valhalla.
Talk to Barid
To begin the quest, meet Barid. He will then be accused of poisoning the Irish soldiers.
To find out who actually did the poisoning, follow Ciara. She apparently knows a druid who can heal them.
Speak to Deirdre
After riding some time with Ciara, she’ll ask you to lead the way.
Deirdre’s location is shown in the map below, marked by the quest symbol.
Just follow the path of runic stones.
You’ll then reach a waterfall area. Deirdre is in the first house.
After talking to Deirdre, you’ll unlock the list of Order members for Ireland. It’s similar to the base game.
You have to find clues to discover their locations. You’ll be asked to find The Wren.
Find and kill The Wren
Your first clue leads you to Port Auley, north of Connacht. The exact location is shown below.
There’s a note inside a house facing the sea. Read the note to get the second clue.
Then, head to a small island south of Port Auley. The exact location is shown in the map below, marked by the player location.
As you reach, you’ll see an altar. Read the note to get the final clue.
Now, head to Rathcroghan. The location is shown in the map below, marked by the player location.
The Wren (Niamh the poet) seems to only appear in the city at night. If you’re here in the daytime, meditate till night time.
Sneak behind her and assassinate her to get the amber shard.
Return to Deirdre
Head back to Deirdre’s location just east of the city.
Take the amber shard to her and the quest ends here.