In the last adventure, the party entered the Mind of Karsus, where an unspoiled version of Phantom's Cloister, called the Monastery of the Fallen One, exists. It is populated by the shades of monks who worshiped the momentary god but now desire only release from their extraplanar prison. Along the way, the party can rescue a relative of the High Lord of Loudwater, Nardine Twohands.
NOTE: Secret of Phantom's Cloister was never publicly released. Information about the content of the adventure is taken from other modules that were released.