The tragedy that befell the Cathcart family was repeated in countless households during the 18th century, and they were certainly not alone as a family ravaged by consumption (now known as tuberculosis). In the case of the Cathcarts, a mother, a father, a son and three daughters were struck down by the illness, but it was the poignant death of the second daughter, Mary, that demonstrated the myriad interconnections between consumption and loneliness during the late 18th century. This chapter explores the ways in which the disease of consumption and its treatments and outcomes intersected with and fostered the conditions of loneliness for Mary Graham (neé Cathcart, 1757–1792) and her loved ones.