The Hall of Many Panes (2005)

An adventure of significant playing length
For six or more experienced players in a well-ballanced adventuring team
(For six D20 player characters of levels 8+)

Contains 3 softcover books for the game master, pages are numbered across the books up to 264. Also a stapled booklet of maps and illustrations.

From the back of the box:
Plunge into the Hall of Panes
Within the etheral darkness towers the Great Hall of Panes. Built in the uttermost depths of time, by the immortal hands of Amadan Mor, the Alfar deity and trickster, the Hall of Panes is a matrix of dimensions. The Hall's depth and height defy imagination as its gently sloping ramp plunges into the great infinite reaches and spirals into darkness. Along its entire reach are shimmering lights, close, yet distant. These are the Panes, gateways to worlds uncountable.