The party camps by the defiled shrine . During the first watch, a tiger emerges from Sam’s tent and attacks Vera and Caylen. The tiger seems magically connected to Sam, perhaps born of his dreams.
In the morning, the party moves south and west, then takes a barge across river. The barge is headed by Officer Gerard in his bronze armor, and crewed by pale slaves speaking Old Ipheran. They are taking marble to a half finished, lop-sided castle beside the river. Inside, a mason named Hobb says his master is trapped on upper floor, and only wants plaster, not marble. Within, the castle is an Escher-esque puzzle. In one room, the party sees rats scurrying around furniture on the ceiling, with innacurate reflections of said rats in the mirror on the floor. A tentacled beast attacks Sam from above a doorway and is slain. Beyond the doorway is an orb with glowing eyes that draws things towards it. In the library, shelves begin on the ceiling and reach towards the floor. Rats have been destroying books and building nests. Tyberion, the architect of the castle trapped above, has left a journal and letters that speaks of the Invisible College. Members are scattered across the expanse, and each is likely dabbling in mysteries they ought not to.
In a shrine is a statue of a blindfolded woman with a lantern and resembles Ustan, but is not quite the typical depiction. Above the shrine is the tool room. Sam arranges a ladder to allow the party to climb up (and climb down) to the tool room. Beyond the tool room is a room with odd angles, and two doors, one iron, one wooden door. Beyond the iron door is Tyberion, who has tried to make his room spherical with plaster. An otherworldly creature attacks, dodging into and emerging from the corners of the room. The party just manages to slay it, saving Tyberion, who rewards them with 500 gold each, and invites them to stay overnight. He shows the party his bizarre architectural accomplishments, including the infinite staircase, a room for guests (with perches,) and a neverending hall, where one is always right at the entrance.