Instructions
Move through the Tomb of Heroes until you encounter Charlie under attack by a horde of Hollow Men. The door to this room shuts as soon as you cross the threshold and will not open.
Defend Charlie from the Hollow Men as he tries to open the sarcophagus in the middle of the room.
Kill all of the Hollow Men. Once you've slain them all, Charlie will get the sarcophagus open and read the note found within. More Hollow Men will attack at this point.
Kill all of the Hollow Men again. The door to the sarcophagus chamber will open when you defeat the last enemy. The main gate in the water room will be locked, but a side door will be open on the right side of the room. Flee through here to escape the tomb.