Revelation 9:1And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit.
2 And he opened the bottomless pit; and there arose a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit.
Here's some nightmare fuel about Rev 6
https://www.calvarychapeljonesboro.org/prophecynews/yellowstone-super-volcano-and-the-revelation-6-effect-part-1