It's a fantasy role-playing game.

DM: You are Vax Vax'ildan, a half-elf rogue . You are the member of the famous group of adventurers. Previously, Stretching away from them are the remains of an ancient city, with a massive obsidian spire at its center. Above them, Vex notices a faint strand of bluish-purple light stretching from the orb, where they emerged, to the very top of the tower, and from the tower down to two other orbs.
DM: You glance inside, and as you peek over the top, in the brief bits of light coming through the shadow in here, you can see the collapsed piles of broken stone and wood planks that used to hold the structure of the upper level together. You can see what looks like furniture that's been destroyed. Simple, basic. This is not an extravagantly decorated space. Built for function, more than anything. But moving amidst the shadow, you see what appears to be a humanoid creature of pale gray skin, elongated limbs, long, clawed fingers. Bald head, pointed, hooked ears, and what looks to be slightly broken, jagged, yellow, elongated teeth in this jaw, as it's currently munching on what looks to be a small furred rodent of some kind. (crunching)
Player: This is probably redundant, but I will Divine Sense undead.
DM: It is very undead.
Player: Do I sense, see, hear anything besides this one?
DM: What's the radius?
Player: 60 feet.
DM: Nothing else catches your attention, no. You watch as it finishes and walks toward the doorway. Vex'ahlia, as you're off to the side, you watch as this creature leans forward and goes into a sprint, and then leaps up onto a distant rooftop. (leaping noises) Just leaping from rooftop to rooftop. As you're watching that leap, another movement catches your eye, and you see another one about three blocks down. You can see, there are at least a handful of these creatures stalking through the ruins, leaping from building to building, from floor to floor.
