Revelation 6:8-10

Revised Standard Version Catholic Edition

⁸ And I saw, and behold, a pale horse, and its rider’s name was Death, and Hades followed him; and they were given power over a fourth of the earth, to kill with sword and with famine and with pestilence and by wild beasts of the earth.

⁹ When he opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the witness they had borne; ¹⁰ they cried out with a loud voice, “O Sovereign Lord, holy and true, how long before thou wilt judge and avenge our blood on those who dwell upon the earth?”