I missed session 4, so this summary follows Session 3.
In previous sessions, the party met a group of Thri-Kreen from the planet Athas. They were in search of a particular botanically-skilled Sensate in the hope that she might help them replenish their magic-ravaged desert planet.
The search for the sensate led them to the gallery of wizards, an art gallery specializing in portraits of powerful mages. The party's visit follows a theft of several paintings in which painting-portals malfunctioned, a sensate disappeared, and a painting of an imprisoned god was vandalized.
This led them into a painting containing a magic labyrinth with a magic healing fountain.
Ultimately we came upon a strange scene: a sensuously dressed woman, rooted to the ground, staring-down an immobilized Minotaur.