A strange, fatal hemorrhagic disease is killing housecats in Camarillo, California. Veterinarian Vera Barnett suspects that the illness originated in the lab of her lover, molecular biologist Noah Chamberlin, who has been investigating a hereditary feline disease at a nearby university.

The infection soon appears in nearby cities and, not long after, all over the world. Senior epidemiologist Angelo Kraakmo, is assigned to investigate. The cause turns out to be a new virus. Angelo names the disease feline hemorrhagic fever, FHF for short. It did not originate in Camarillo.

Newspapers report FHF mortality figures on their front pages. Rodentborne diseases become epidemic. Cat-oriented businesses suffer severe economic losses.

Vera, Noah and Angelo work together to find a cure. By the time eighty percent of the world's cats have perished, scientists question whether the species can survive.

Will Felis catus become extinct? What are the consequences of the demise of a species that has lived intimately with humans for twelve thousand years? How will the disappearance of our feline companions affect the human population?