Revelation 6:8-10 Revised Geneva Translation (RGT)
8 And I looked. And behold, a pale horse. And his name who sat on him was Death. And Hell followed after him. And power was given to them over a fourth of the earth; to kill with sword and with hunger and with death and with beasts of the earth.
9 And when he had opened the fifth seal, I saw, under the altar, the souls of those who were killed for the word of God, and for the testimony which they maintained.
10 And they cried with a loud voice, saying, “How long, Lord - Who are holy and true - do You not judge and avenge our blood on those who dwell on the earth?”