Throughout the fight, the room was illuminated by a curious magical lamp with a vellum lampshade hanging from the center of the ceiling. But as the last orc died, the light extinguished and the adventurers once again had to depend upon their torches.
Upon closer inspection, the base of the light proved to be a hilt of elven make, and inside the shade was the rest of an elven dagger, crudely coated with a layer of glass.
As the PCs are in the midst of looting the room and discussing how to get the light fixture down, it lights back up, much brighter this time...
If they survive the next wave of orcs to retrieve the light fixture, they find on the hilt, in rough orcish script "Ozgurk's Elven Blades - Ecologically friendly, energy efficient lighting for the Orcish