Eel has been a mudlark – a boy who lives off of what he finds on the banks of the Thames – during the Victorian era. He now lives in Soho where he works as an errand boy at a brewery. When people begin to fall ill and die, Eel learns that the telltale sign of blue lips is indicative of cholera. Within days the Great Trouble is in full swing – the cholera epidemic that would take over 600 lives in the poor, overcrowded homes in Soho. Eel makes extra money by helping out around a physician’s house. It is this doctor, John Snow, who is convinced that cholera is not spread by the miasma (bad air) in London but through contaminated water. With Eel at his side they set off to prove that a particular water pump on Broad Street is the epicenter of the epidemic. This is a wonderful medical mystery, an informative read about a killer disease (the backmatter is terrific), and a terrific taste of Dickensian London.