The Time of the Fourth Horseman (1976) is an apocalyptic novel concerning the Modest-Proposal-style decision of some doctors at the top to kill off the excess population by using placebos for one third of all the vaccinations for diphtheria and typhoid and such illnesses. Of course epidemics rage and the diseases mutate into unstoppable forms. Horrors dominate.

Firecode (1987) belongs to Yarbro's second most typical form of fiction, the apocalyptic or holocaust novel. As with False Dawn and The Time of the Fourth Horseman, she appeals to the reader's paranoia to create a sense of helplessness in the face of mass death and destruction. Here, the fear is that of the innumerate who fear the dominance of computers and their incomprehensible "number-crunching" in the late twentieth century. Needless to say, the computers bring ruin to humankind.

The central character is a statistician named Carter Milne. When a series...