Lot

Rist's arbalester skitters along down the tunnel, pausing occasionally to make sure you're still following. You estimate that the tunnel is only about forty feet long, but the twists and awkward angles make it take longer than expected to reach the other end. When you do reach the exit, you discover the reason for the sounds you heard in the main chamber: the tunnel stops suddenly and opens into a great yawning void, and strong crosswinds ruffle your clothes and pelt it with pebbles as you approach the opening. The stone is flat for several dozen yards around the opening, at least, as if the opening is in the middle of a cliff face and you are looking down the side...except that you see no ground at all, the stone just ends.

Suddenly, a sheet of flame fills the air in front of you, stopping about a foot in front of your face but otherwise filling your vision. The heat is painful, but bearable, and moments later the flame dissipates. Once the afterimage is gone, you can make out several floating objects of various sizes in the distance, some large enough to be floating mountains or the like and some small enough to be flying creatures and everything in between. Small bursts of fire, waves of water, and chunks of stone pop in and out of existence as you watch. It seems the Churning Chaos lives up to its name.

Rist

Your examinations tell you that this gate ring is very similar to the one in the AGC back on Eberron. Of the few arcane runes you recognize, most relate to interplanar travel and the rest relate to wardings of various sorts; none give you any hint as to how to control the ring. All the other runes are beyond your comprehension; as one of the Zil elemental binders in the AGC put it, trying to figure out this device is like a Brelish schoolchild trying to work out a tensor calculus problem written in Aerenal, an analogy made even more appropriate by the fact that most of the artificers he was talking to had no idea what "tensor calculus" was.

One thing you do know, however, is that to everyone's knowledge the Eberron gate ring's gem-studded artifact from Xen'drik was unique; they didn't mention discovering any other such artifacts during their recon, and they seemed to believe that their artifact just opened gates willy-nilly. Given your new information that the gate ring is not, in fact, unique, the topaz embedded in the ceiling in the middle of the ring would seem to be another control artifact buried in the rock face. You would probably need to dig it out to work the portal device from this side.