I wasn't feeling all that great the last session, so it ran a lot shorter than usual and was pretty sedate to boot. Nevertheless, the characters gleaned a few new pieces of information that seem to given them greater insights into recent events in Dwimmermount.
As you may recall, at the end of the last session, the party captured a human magic-user who'd been employing bugbears as muscle on Level 4 of the dungeon. Brother Marius, Brother Candor's novice, successfully cast hold person on him and this left the characters with a decision about how best to interrogate the magic-user. After briefly considering whether to question him within Dwimmermount, they decided instead to take him back to their home in Muntburg. Once there, they tried to use non-magical persuasion -- and threats of violence in the case of Dordagdonar -- to get their captive to speak. He proved completely unwilling to do so, so the characters decided to use a charm person spell on him on the next day (as none of the party's spellcasters currently had it memorized).
The captive later succumbed to Dordagdonar's magic and happily answered any questions the PCs had of him. He explained that he was a Termaxian Magister sent to investigate reports that Dwimmermount was again accessible to the outside world. The character expressed puzzlement at this, as the magic-user did not dress in the same attire as the Termaxian cultists they'd encountered deeper in the dungeon. The magic-user, whose name was Fulk, at first did not understand why the characters were puzzled but soon realized that, as "barbarians," they'd only be familiar with "the false Termaxians." This led to yet more confusion and a barrage of additional questions that took up a large portion of the session.
In sum, Fulk explained that he, like all the Termaxian Magisters, served the Thulian throne, whose emperor had sent him specifically to see if Dwimmermount was again active. The Termaxian Magisters, it seems, are an order of magic-users who serve rather than control the Thulian Empire, despite the fact that, so far as the characters know, the Thulian Empire fell several hundred years ago. Fulk admitted that, yes, the Empire had lost much of its former dominions, including the area around Dwimmermount, but it never "fell." Instead, it's been regrouping and consolidating its "loyal" territories in preparation for a reclamation of those provinces lost to the barbarians. Fulk also added that the "false servants of Turms" had usurped the powers of the emperor in the past and it was their heresy and arrogance that led to the Empire's current predicament.
Brother Candor found this revelation quite odd, as so far as he knew, the Thulians were cast down long ago. If they still existed somewhere, it'd have to be far from the area around Dwimmermount, perhaps to the north on the Isle of Thule itself. Fulk did speak Low Thulian -- the Common of my campaign -- with an odd accent, so he was clearly not from nearby, so there might be some truth to what he was saying. That the magic-user explained that the Empire employed humanoids like bugbears as "auxiliaries" didn't make any feel better at the prospect of the Empire's persistence after its presumed fall. After asking a few more questions, the characters released Fulk and gave him a horse so that he could head back to Adamas (which he called "Fort Adamantas") and returned to him his possessions, over the objections of Dordagdonar. Brother Candor felt there was no need to antagonize him, as he wasn't their enemy and might, in fact, prove to be an ally later, depending on the nature of the Thulian Empire he said he served.
The next day, after memorizing new spells, the party headed back to Dwimmermount to seek out an entrance to the House of Portals. Along the way, the encountered a series of chambers that were clearly summoning room/nexus points to the Elemental Planes, as well as other rooms with strange crystalline sculptures within. These sculptures were in fact arcane locks that barred advancement further unless an appropriate spell was cast upon them. The characters figured out the proper spells to cast in several cases and were able to move forward, albeit slowly, before stopping in a room containing a large sapphire Brother Candor suspected was a soul jar or something similar. Unfortunately, all efforts to use it to open the barred door ahead failed and the party found themselves unable to travel further. For the moment, the way to the House of Portals continues to elude them.