“The rain came in west Africa. A massive wind blew in from the Atlantic coast bringing the deluge of water known as the south-west monsoon.”

IT is fitting that there is quote early on here from Edgar Allan Poe. Before science gave us its ghastly, rational explanations, plagues must have seemed like acts of god, revenge for heathen activities, out of the heavens awfulness. Here Crosby tackles one of the big ones, yellow fever, so called because post death the corpse literally turns to nicotine yellow. “Unlike any other disease (it) carried a mysterious horror to it. Its attack was acute and quick, its duration painful.” It struck so suddenly that sometimes someone would say: I think I have the fever, I will just go and lie down. And they would be dead in the morning. Crosby who lives in Memphis focuses on that town’s epidemic of 1878 which proved especially virile. “In July the city boasted a population of 47,000, by September 19,000 remained and 17,000 had yellow fever.”

She has a cinematic eye for the details, the mosquitos in the hold of the ship in Africa, the slack evasive quarantine in New Orleans, the two nuns arriving at a stricken house “a yellow card on the door swinging from a nail”, letters from a husband who stayed behind, the telegram that reads: “Father and mother are lying dead in the house, brother is dying, send me some help, no money, Sallie U”.

We also have the medical detective story. Quarantine – from the Italian for 40 which was how many days ships were held at anchor before being allowed into port –  was the only defense. The idea that a third party might be involved – mosquitos thriving off the filth of a pre-sewer urbanity – would take decades to be understood and the story would move on to another stricken island and entry point for this deadly immigrant, Cuba. It would make good horror cinema this, a mix of Deadwood meets killer zombies (one side symptom saw people going mad and running the streets screaming), the faction is relayed with the compelling, frightening prose of a Michael Crichton thriller staged with meticulous details of late Victorian scenery culled from newspapers of the time.

On the way Crosby drops a few by-the-bys as to the emergence of modern medicine, how children were preferred guinea pigs as blank slates (Edward Jenner who found a vaccine for smallpox destroyed the life of his own son by testing on him), doctors might self experiment (William Hasted self-tested the anaesthetic puissance of cocaine) and here new immigrants were covertly signed up into medical programmes. Soldiers though often volunteered, aware perhaps that their chance of dying of disease was much higher than in some bloody battle and their survival much more likely under controlled hospital conditions.

To disprove the idea that yellow fever might be a germ or transmitted by humans,  soldiers were quarantined in barracks with the dirty sheets and detritus from the yellow fever ward and emerged weeks later unscathed. In parallel, the doctors self infected themselves with bites from the female striped house mosquito…one died and another was irreversibly affected for the rest of his life. As with all great fiction, it is the villain that is the real star in the story, but one she warns that has probably not gone away and lingers on in African and south American jungles, incubated by monkeys…and biding its time.