The Morgue is a side room of the Cistern Entrance where dead bodies are stored.
The Morgue was used by Alexander to store corpses, possibly using them for study. It could have also been used to demoralize and terrify Alexander's test subjects, suggested by a Flashback. In order to survive the toxic fungi in the Sewer, it is necessary to get vaccinated with the blood from a day-old dead body lying on a table in the Morgue.
A note on a nearby table explains that the transfusion of blood from a person who has already had the vaccine will provide enough protection to pass through the sewers unharmed by the fungi. To get the vaccinated blood in your circulatory system, you must first use the hand drill to bore into the skull of the deceased lying on the table. After boring a hole into the skull, you need to assemble a syringe using the Hollow Needle acquired earlier in the game and a Copper Tube found in the Morgue. After creating the syringe you can then use it to inject yourself with the blood. Once you have been vaccinated, a Brute will start breaking down the door (or on rare occasions will destroy it instantly) when you attempt to leave the room. You can avoid it by retreating into one of the two adjacent rooms. Both rooms contain a pile of corpses that will drain Daniel's Sanity; one room is large and contains a stone walkway around the perimeter, and the other is small with a low level of water on the floor. Either room can serve as an adequate hiding place. Despite the amount of light in the room with the stone walkway, there is a small staircase on the far side which Daniel can safely crouch behind. The room filled with water contains dark corners sufficient for hiding, granted Daniel doesn't make any sounds like jumping or walking while in the water.
- The operation with the dead body will drain Daniel's sanity, because he has to look at it at least momentarily to place the drill and syringe. The actual injection will cause Daniel to faint (vasovagal syncope), and when he gets up, he will be woozy and at lowest sanity. This is scripted into the game and is unavoidable.
- If the Brute attempted to kill Daniel for the second time, the Shadow will consume the area.