In the secret alcove behind the picture on the wall at the south west end of the hallway. You need to use the Unicorn Medal on the small indentation below the picture to reveal the alcove.
Inside the locked cabinet opposite the door leading to the night-duty room in the north west corner of the corridor. Requires Alyssa's lockpicks to open.
Inside the locked cabinet opposite the door leading to the night-duty room in the north west corner of the corridor. Requires Alyssa's lockpicks to open.