Place castle tiles as usual.
Ghosts only get added depending on mist placement (see Placing Ghosts and a Meeple) when placing a castle.
As in the cooperative game, you can place a meeple on a castle. It doesn’t need to be guard meeple , you can also place a base game meeple .
You score a castle as soon as it is completely surrounded by tiles (like a cloister or cemetery). Score 2 points for each surrounding tile with mist on it (including the castle tile itself).