When the Lamb opened the fourth seal, I heard the voice of the fourth living creature say, "Come!" I looked, and there before me was a pale horse! Its rider was named Death, and Hades was following close behind him. They were given power over a fourth of the earth to kill by sword, famine and plague, and by the wild beasts of the earth.
This composition brings to mind the idea of the thread of life, suffocatingly stretched, as if the rider is about to cut it, and with it the last breath of thousands of people on earth is gone.