I have only played this scenario one time, but my guess is that this event happens each time. Once you walk into the mansion, you hear a crash in the other room and are shown that a barrier could be used to block off the door. Instead of going into the room and see what caused the noise, we just blocked the door right away with the barrier. I believe 2 turns later the app tells us that a monster appears from the room where the noise happened.
Do we spawn this monster and leave the barricade still in place, OR does this monster appear off the board and need to break through the barrier?
Thanks!