Assassin's Creed Valhalla is full of quests and among these, we find alliance quests. AT grantebridgescire, you will try to make friends with Soma's Summer Army. When you have found her and her lieutenants, she will decide to launch an assault on her city, which has been captured.
After the battle, she will talk to you and give you a mission which is to find the traitor among these 3 trusted men with the quest " The stench of treachery ". So find below how to know the traitor.
How to identify the traitor during the quest "The Stench of Treachery" in Assassin's Creed Valhalla?
To find the traitor, you will first have to find the 3 suspects. Each will have a quest for you, but before starting their quest, talk with them to learn more about each of them.
After talking to the 3 characters and completing their mission, you can return to Soma who will have captured a Saxon soldier.
Once the cutscene is over, you can continue your investigation by following the tunnel and at the end of it, you will find a yellow cross.
Here, Lif just told you that someone stole his yellow paint, so you can partly dismiss suspicion on the latter. All you have to do is find out who the traitor is between Birna and Gallin.
Then head north at the location of the green arrow on the map below.
You will then find a ship from the Soma fleet whose bow is painted yellow. Then interact with the text inscribed by Lif to discover the culprit who is Gallin since there is mention of a vision depicted by a volva and you will therefore suspect that the boat belongs to the latter.
Now that you've figured out who the culprit is, all you have to do is go back to Soma and blame Gallin.