Apollyon: Left Behind Series, Book 5

The Tribulation calendar moves ever closer to the halfway point, which the two witnesses call "the due time." Meanwhile, the fourth Trumpet Judgment strikes the solar system, crippling life on earth. The next three judgments are to be so much worse than anything that has come before that an angel flies about heaven, warning the earth of the three woes. The fifth Trumpet Judgment, a plague of scorpion-like locusts led by Apollyon, chief demon of the abyss, is so horrifying that men try to kill themselves but are not allowed to die.