A13 Chain Bridge
This chamber slows the progress of the PCs, since they must negotiate a pair of moving platforms across a deep chasm. In addition, two fiendish creatures are bound to the chamber, manifesting to attack as the PCs try to cross the gaps.
The stairway widens as it opens into a wide chamber, but the floor ends precipitously after 10 feet. A deep chasm splits the room, with three massive metal platforms suspended above it by chains hanging from the ceiling. The nearest platform is perhaps 10 feet wide and 20 feet long, like a bridge that crosses only half the distance to the central platform. The chains it hangs from are pulled taut toward you, as if some unseen force holds the platform in place. The central platform is much wider but only 10 feet across. The third is another half-bridge stopping short of the far wall.
From the bottom of the chasm 80 feet below, molten lava illuminates the platforms with a dull red glow. At the floor’s edge closest to you, two draconic-looking humanoid statues stand sentry, their cold eyes seemingly watching you. Two identical statues stand on the opposite side of the chamber. Above you, sparkling in the dull red light, a crystalline shard is set into the ceiling in the center of the chamber.
PCs who take a closer look at the two smaller platforms note four chains hanging at regular intervals across the ceiling, two over the current positions of the platforms and two hanging in the empty space beyond them. Pulling the chain over a platform causes it to move into the empty space ahead of it at a speed of 10 feet per round, putting it into position beneath the other chain when it stops. Pulling that chain then moves the platform back in the other direction.
The shard imbedded in the ceiling is a Khyber dragonshard, implanted with a specific purpose. When the dragons defeated the fiend that created the Altar of the Dragon’s Eye, they also captured its minions. Three of those creatures, a few of the canoloths, were trapped within the Khyber shard and forced to remain here as guardians of the altar. The canoloths are able to manifest within the chamber, though their confinement has stripped them of their spell-like abilities and their ability to summon other yugoloths. They appear as soon as any PC starts moving across the chamber.
Development: When slain, the canoloths dissipate into wisps of acrid smoke and return to their shard prison. Their defeat is only temporary, however, and each can return to the room after 24 hours unless the shard is destroyed.
Ad Hoc XP Adjustment: Increase the XP award for this encounter by 50% due to the tactical nature of the room.