Gneiss moves over to the foot of the stairs, leaning forward and craning his neck to see as far up as possible. Pausing, he calls back to Gilthanas, "I'm going up a little way to keep an eye out. You lot hold on here for now." Suiting actions to words, he advances slowly and cautiously up until he passes out of sight.

Spoiler
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Spot: (1d20+9)[14]
Listen: (1d20+9)[15]
Hide: (1d20+9)[21]
Move Silently: (1d20+9)[16]

Gneiss is looking for a niche or alcove where he can wait in ambush for any draconians heading down. If he doesn't find anything suitable by the time he reaches the next floor, he'll try hang back on the stairs out of sight of people passing by - even if the best he can do is stop a few steps short of the landing so that his head is below floor level.