Revelation 6:8-10 J.B. Phillips New Testament (PHILLIPS)
8 Again I looked, and there appeared a horse sickly green in colour. The name of its rider was death, and the grave followed close behind him. A quarter of the earth was put into their power, to kill with the sword, by famine, by violence, and through the wild beasts of the earth.
The cry of the martyrs in Heaven
9-10 When the Lamb broke the fifth seal, I could see, beneath the altar, the souls of those who had been killed for the sake of the Word of God and because of the faithfulness of their witness. They cried out in a loud voice, saying, “How long, O Lord, holy and true, until you judge and avenge our blood on those who dwell on the earth?”