Finding Sokolov | Mission 4 - The Royal Physician Dishonored Guide
Last update: 11 May 2016
As I have already mentioned, Sokolov is staying in the greenhouse on his mansion's roof. If you have chosen to get here through Sokolov's building, you need to get to the second floor and find stairs to the roof (the above screenshot).
If you have got here without exploring the building, you just need to get to the upper balconies patrolled by a single guard (the above screenshot).
Regardless of how you got here, you need to take the door to Sokolov's Greenhouse (the above screenshot).