Walkthrough: The Death of Hannelore
Objectives:
Take out the guard located in the front yard. Take his clothes, hide the body (you know the drill). Head to the left where the two bodyguards are keeping watch. Enter the door and proceed to room on your left (identified as a "Point of Interest" on your map with a "!"), there you'll find the white gown which will grant you access throughout the hospital.
Pull up your map to locate the Agency's supply drop point. To reach the drop point, you'll have to remain patient until the lone guard decided to take a visit to the restroom. Once inside, follow him and take him out with your fiberwire. Then hide his body, since the other guy in the other stool is bound to notice and mess things up for you.
Don't be concerned with using weapons here, just grab the key and the poison, and then head to the waiting room which leads to the second floor. Walk up the steps normally and you'll be greeted by a secretary who will mistake you as a patient. When she turns her attention away from you, drop the poison into her class. Sit through her Chatty Kathy ramble, and eventually she'll take a sip from her class. Eventually she'll fall over and now it's time to move on. When a patient heads up the steps, use the chloroform method (or fiberwire). Hide his body and exit the building.