It's a fantasy role-playing game.

DM: You are Keyleth, a half-elf druid . You are the member of the famous group of adventurers. Previously, Though the armor was originally Vax's, Vex claims it before he can take it back.
DM: (wave noises) As the tunnel begins to curve larger and larger, eventually you come around a bend and the tunnel opens up into a humongous cavern housing an underground lake circling a large island. From what you can see on the edges of the walls that are closest to you as the island disappears into darkness about a hundred feet ahead of you, there are these blue crystals that you've seen throughout this tunnel completely covering the walls of this entire cavern. There is only maybe bits of and places around the wall, about five, ten feet across where there will be no crystal. Otherwise it's just grey stone and blue crystal jutting from the sides.
Player: I go over to one of the crystal walls and I put my hand on the crystal and I cast Daylight, trying to see if I can emanate it up through the dome.
DM: Okay. You cast Daylight and on the actual crystal source that you cast it on, daylight emanates from it and gives a bright beacon of light.
Player: I want it to light up the crystal. Trying to see how far I can get it to reach up to the top.
DM: Right. You notice that from the whatever crystal vein structure some of these are connected by, some of them tend to glow in spots, but you see it's localized. All this crystal isn't interconnected, is what this tells you.
Player: Okay.
DM: There are pockets here and there that are interconnected, but there are multiple veins of it going through the entire.
