Hi, I had a burthorpe task of 16 ghosts and I went to melzars maze, but you need a red key dropped by a zombie rat to get to the door and climb up the ladder to the room with the ghosts. So I killed some of the zombie rats but they didn't drop them, but there was 1 zombie rat and if you attacked it it said in the chat box: You can only attack that monster while you are doing the Dragon Slayer quest. So only that rat drops the key now and if you have done the dragon slayer quest you can't get the key anymore! I think jagex changed it in an update.