In an 1857 Saturday Review article about the novel Two Years Ago, T. C. Sanders characterises Charles Kingsley's ideal man: he ‘fears God and can walk a thousand miles in a thousand hours – [he] breathes God's free air on God's rich earth, and at the same time can hit a woodcock, doctor a horse, and twist a poker around his fingers’ (qtd in Haley 1978: 108). Tom Thurnall, the fearless, constitutionally robust, well-travelled doctor and hero of Two Years Ago (1857), fits these requirements. His physical strength also manifests as a charmed immunity to illness: during a cholera epidemic in the fictional Cornish town Aberalva, ‘[Tom] thought nothing about death and danger at all … Sleep he got when he could, and food as often as he could; into the sea he leapt, morning and night, and came out fresher each time’ (1857: 288).

For the majority of Aberalva's fictional inhabitants, not blessed with Tom's iron constitution, disease is a particularly terrifying foe, omnipresent but invisible:

Disease is retributive in Charles Kingsley's schema, punishing those who choose to live in close, cramped quarters and who refuse the vigorous physical activity that God intended. The men's terror in this excerpt stems not just from disease's invisibility, but also from the sense that they could be already carrying cholera with themselves unawares. They must ask an acquaintance to read their own death sentence imprinted upon their features. Thus, the vulnerability felt in the face of disease is compounded by dependence on one's neighbour. Both reliance and gratitude are even more acute when the neighbour has some medical training or ability. The inhabitants of Aberalva express pathetic regret that they did not listen to Tom's exhortations to space themselves out and become more active before the cholera arrived. They now turn to him with frantic appeals to save them from their fate.