Gathering his wits after his initial astonishment at his loss of visibility around him, Guran latched upon a new plan: play it just like the crazy "fog game" he had learned as a child.
Dwarves, of course, can see in the dark; but even they found that there were some nights when they would still bump into unseen things as they walked around in the darkness -- and those nights were the ones in which a thick fog lay on the ground. Their usual courses of action were either to stay indoors and not try, or else to walk bravely forth through the fog with one hand sweeping left and right ahead of them, touching walls on the outside of each sweep in order to maintain a steady course, and always slowing to a stop if they touched anything in front of them.
Guran decided to use the "fog game" to advance up to find Colden, whom he had last seen a couple of squares ahead of him. If Colden had moved, Guran would not find him there; but if he hadn't, then Guran could encourage Colden to advance by shoving on his back. While not necessarily a good plan, it was better than no plan at all. Guran carried his short sword in his right hand, so he made the sweeping motions of "the fog game" with his left, advancing diagonally out of the mouth of the hallway into the corridor ahead, reaching for Colden's back as he did so. He took another couple of steps, but did not find Colden where he imagined the fighter had been.
Thinking Colden must have advanced already, Guran kept going. When he got to a point that he imagined was just past where Colden had been, the floor suddenly became slippery, and the wall on Guran's left was no longer there. Thinking he must have passed through a doorway, Guran edged farther left and eased across the icy floor another 5 feet, this time diagonally to his left [northwest], sweeping his left hand in the air to brush the door that was ajar there and back to reach toward his right. He could not hear the incessant "snarfling" of kobolds because the conscious ones were still hidden from him by both darkness and silence.
When Guran walked past the edge of the door and lost contact with it, he suddenly found his hearing returning. He had found the boundary of whatever spell had made the sound go away!
Another half-step brought him within sight of Colden at last. So there he was!
Wait: SIGHT! He could see again. Guran took in as much as he could at a glance, and it was more than enough. Yeah, the bad guys had a dragon. Fine. One to more pressing pursuits: Spec was down on the floor and bleeding; and there was a dark elf holding a leash that was attached to the dragon.
Stopping right where he was, Guran cast "Healing Word" on Father Spec as a bonus action, restoring a small smattering of hit points to the cleric.
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Fully out of spells for the day, Guran stabbed at the dark elf holding the leash. (Guessing advantage for having been hidden, and sneak attack because Colden is adjacent to the target.)
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