In the aftermath of the Civil War, the black staff at the Lazaretto quarantine hospital the first stop for immigrants who wish to begin new lives in Philadelphia find the wedding plans for one of their own marred by a shooting.

At an internment camp in Indonesia, forty-seven people are pronounced dead with acute hemorrhagic fever. When Henry Parsons - microbiologist, epidemiologist - travels there on behalf of the World Health Organization to investigate, what he finds will soon have staggering repercussions across the globe: an infected man is on his way to join the millions of worshippers in the annual Hajj to Mecca. Now, Henry joins forces with a Saudi prince and doctor...

"A mysterious plague known as the Grey grips the small village of Pilam, which the world has quarantined without pity. Laying waste to Pilam's residents, the sickness saps its victims of strength, drains the color from their eyes, and kills all promise. Only the young are immune. But beyond the barricades and walls of soldiers, the manifestation of a nation's terror, there are rumors of a cure. Dunka, the eldest son of a family reeling from the Grey,...