The Day after Judgment is an exhilarating and hair-raising sequel to Mr. Blish's Black Easter, the two connected books now forming the centre-piece of a trilogy, flanked by Doctor Mirabilis and (still the best) A Case of Conscience, in which the author has aimed to dramatise, in terms of Science Fiction and black and white magic, some of the questions already posed by Milton and Marlowe concerning the powers of God and Satan, the nature of the demonic and the reach of human knowledge. In the present book, Armageddon appears to have arrived, God to have died and Hell to have pushed through to the Earth's surface in Death Valley, California. Can demons be destroyed by material weapons of ultimate sophistication? If so, should they be? Or would the result of that be even worse, since spiritual good and evil are interdependent? The Strategic Air Command, introduced with some satire, has no inhibitions, but the climax is very exciting. A perilous pastiche of Miltonic blank verse makes the end wobble a bit.