Mission 5: Lady Boyle’s Last Party
Rune 5-1 / Outsider Shrine 5-1
When you start the mission, go up to the street and to the left towards the security checkpoint. Make a right from there and enter the doorway in the red wall. Follow the stairs up and you will come to a blue open door. Inside will be an Outsider Shrine with the rune on it.
Hop in the water at the far end of the river running through the center of the city. The rune will be located in the center, under the water.
To find this rune, go down the stairs on the left of the courtyard entrance inside the mansion and go through the kitchen to follow the passage to a barred door. Use the switch on the right to open it and then go to the far right corner. You will need to get the vault key from the desk in Lydia’s room on the second floor to open the vault door first. Her room is on the second floor which you can get to by taking the stairs to the kitchen up instead of down.