This page offers a guide on The White Lady of Tamworth, which is a Mystery located in Ledecestrescire, Assassin’s Creed Valhalla.
Kill the Guard
This mystery is located south of Tonnastadir. When you approach the tower, you’ll hear a lady from within crying for help. You’ll need to defeat the man who guards the tower. Upon doing so, however, you’ll discover that it was all a bit of roleplay and that the woman is not actually being held captive.
The lady will then ask that you stand guard for her, and you’ll need to interact with the spot in front of the stairs to actually begin your guard duty. A man will approach the tower and you’ll need to defeat him as well. After doing so, you’ll have completed the mystery and earned 1,200 EXP.