In which the Great South Central Pacific and Mexican Railway emerges as a popular yet enigmatic venture, drawing in gentlemen of varied repute who navigate its murky waters with differing degrees of understanding and profit. Amidst whispered suspicions and social manoeuvres, Paul Montague wrestles with uneasy conscience and newfound wealth, while his colleagues debate their own stakes and grievances under the watchful eye of the formidable Mr. Melmotte.