Lucifer's Hammer is the story of the aftermath of a comet's impact on Earth in the middle of the twentieth century. The story revolves around an enormous cast of characters including a US Senator trying to hold America together in the wake of the comet's impact, a scientist suffering from guilt at having predicted that impact was unlikely, and a fanatical evangelist leading a doomsday cult. The novel depicts humanity's struggle for survival in the ashes of society.