Boardgamegeek https://boardgamegeek.com/boardgameexpansion/144777/mice-and-mystics-heart-glorm
English - Prince Collin and his friends defeated Vanestra and thought evil had been banished from the castle forever. But deep within those scorched and shadow-haunted halls, something is moving that should not be.
Ludovox http://ludovox.fr/jeu-de-societe/mice-and-mystics-le-coeur-de-glorm-6854/
French - L'histoire de cette extension se déroule juste après les événements de la boite du jeu de base, auxquels avaient pris part le prince Collin, Maginos, Tilda, Nez, Rusard et Lily.