As the massive door opened wider still, Daniel saw that the room behind the wall mirrored the visitor's bay in every respect, except that it was completely empty.
Oh, and except for the blinding gash of pure white energy floating in the air in the center of the chamber.
So, yes, if you ignored that, the other visitor's bay was completely empty.
The gash of light was wreathed in dozens of flowing streams of green and blue mist, which flowed helically around it. Each strand of colored fog moved faster than any natural or artificial cloud Daniel had ever seen.
The object floated perpendicular to the floor, and as he watched, the fissure of light twirled in upon itself, like a string wound tightly at both ends.
It then collapsed into a single point and vanished. The other visitor's bay went dark.
With a flash of even brighter light, the gash reappeared. It looked the same, but it now floated parallel with the floor.
The anomaly vanished and returned several times every 30 seconds, randomly changing from horizontal to vertical to diagonal.
The object made no sound.
And even in the depths of his despair, Daniel felt a sort of reverence for the beautiful, silent hypnotic cipher in front of him.
However—it should be noted—he did not have enough reverence to hold in his gas.