'When the rains fell, the world burned...' After a childhood spent in the foster care system, failed PhD student Amy Weston attracts trouble wherever she goes. Acid rain is destroying London's trees, brain lesions are turning once-harmless pets into killer dogs, and her new work colleague, Professor Joel Harket, is the most infuriating man she has ever met. But when the media continue to insist that autumn has simply come early, and humans begin to experience the same symptoms as the killer dogs, Amy must work alongside Joel in order to convince the world of the seriousness of the situation, before it is too late.

From the UN Air Health summit in Beijing to the abandoned tunnels beneath the city of London, Amy and Joel search for answers to prevent the end of the world, and as Nelson's Column crumbles and zombie-like 'howlers' wreak havoc worldwide, they discover that the only way to survive the apocalypse is to set aside their differences... and learn to trust each other.