Revelation 6:8-10

Amplified Bible

⁸ So I looked, and behold, an ashen (pale greenish gray) horse [like a corpse, representing death and pestilence]; and its rider’s name was Death; and Hades (the realm of the dead) was following with him. They were given authority and power over a fourth part of the earth, to kill with the sword and with famine and with ^[a]plague (pestilence, disease) and by the wild beasts of the earth.^(A)

The Fifth Seal—Martyrs

⁹ When He (the Lamb) broke open the fifth seal, I saw underneath the altar the souls of those who had been slaughtered because of the word of God, and because of the testimony which they had maintained [out of loyalty to Christ]. ¹⁰ They cried in a loud voice, saying, “O Lord, holy and true, how long now before You will sit in judgment and avenge our blood on those [unregenerate ones] who dwell on the earth?”^(B)