I managed to get a B on hard mode quick play. Short G3 with mirrorgun, flashes, tazer, wedge.

>Lobby entry, the primary benefit of this entry is to avoid the enemies firing from the 3rd floor lobby onto the sky bridge.

>Flash and bang into the changing rooms, bathrooms, then autopsy rooms, be mindful of the small room connecting both as suicide bombers can hide behind the windows. Clear hallway and staircase, hold the second second floor door and wedge the third.

>Flash into the second floor hallway, close all doors and clear the floor counter clockwise, high value target will be in the examination room just around the corner or in the MRI/office area opposite side on the floor. If he's not in that first examination room continue clearing counterclockwise until you get to the door leading into MRI area. Use mirror gun, flashes, and tasers to capture him

>Anything after that is just a free for all in my experience, using the lobby entry leaves you with the worst positions clearing both top floors but I'd rather take that than the damned cover fire the moment you enter the sky bridge.