EVIDENCE!

Dr. John Snow, “the father of modern epidemiology,” discovers the cause of cholera.

Behind every great scientist is evidence. When cholera broke out in London in 1854, most people blamed the “bad, smelly air” for the rapid spread of the disease. The English physician Dr. John Snow had a “bold hypothesis.” He had noticed that cholera’s symptoms included vomiting and diarrhea, so the cause was likely what the victims had ingested rather than something airborne. All he needed was evidence! With expert pacing, Hopkinson sets up Snow’s story as a medical mystery and a race against time. The doctor follows clues, gathers information about where the deceased people lived, plots his data on maps, notices clusters of disease, interviews local residents, and discovers the one thing the dead had in common: They had drunk from the same water pump. Henderson’s moody, expressionistic art captures Londoners’ confusion and concern, while Dr. Snow’s urgent pace is marked with literal dashes across city maps. Hopkinson nimbly acknowledges when she’s using conjecture—“We can guess the hard questions he must ask”—and makes clear when she’s presenting evidence: “This fact is helpful.” At the story’s climax, Dr. Snow presents his findings at a neighborhood meeting, and in a final, incandescent spread, the water pump’s handle is removed—“a milestone in science, a shining moment in the long fight against epidemics.”

A page-turning medical mystery that makes a compelling case for following the facts.