A medical historian with a focus on epidemiology, likely also being a doctor or having a strong academic background in medical science, who appreciates the evolution of disease understanding, public health strategies, and outbreak prevention methods.
The year is 1854, and a chilling fog hangs heavy over London, mirroring the unseen menace of cholera that stalks its unsuspecting victims;  I recall the grim determination on John Snow's face as he meticulously mapped the disease's spread, a pioneering effort that would forever alter our understanding of disease transmission.