for a couple of hours at low tide each day. It had claimed the lives of sailors and sunk ships for hundreds of years, but its situation caused difficulties in producing a design that would stand up to the storms and waves that ravaged the area while simultaneously housing the builders who worked on it during the few months of fair weather available each year. The Sewer King Set in London during the 1850s, this episode focusses on the construction of the London sewerage system, built to replace the antiquated medieval system that was overworked and inadequate for the needs of the then-largest metropolis in the world, causing epidemics of disease and a permanent foul stench to fill the air also known as the Great Stink. The episode follows the efforts and work of Joseph Bazalgette, the brilliant engineer who designed the influential and modern sewer system that would purify the city, transform the streets above and would result in the end of the epidemics of cholera and typhoid that had ravaged the population—although, ironically not for the reasons that he initially thought. (This episode was written by Gregory Evans and directed and produced by Bazalgette's great-great-grandson, Edward Bazalgette) The Panama Canal This episode presents the French and American efforts to build a canal through Panama to link the Atlantic Ocean with the Pacific Ocean. The first attempt to construct the canal by Ferdinand de Lesseps, the builder of the Suez Canal, was abandoned because of tropical diseases (which killed over 22,000 men) and the difficulty of constructing a sea-level canal through the mountains. The resulting financial scandals not only ruined de Lesseps and many investors, it also brought down the French government. The episode then takes up the story seventeen years later when the United States took up the challenge. A concentrated effort succeeded in eradicating the causes of the tropical diseases, but the attempt to build a sea-level canal once again failed. Instead the canal was built with locks. The Line The episode follows the construction of the First transcontinental railroad, the first transcontinental rail system, which would unite the eastern and western seaboards of the United States. Started in Sacramento by a consortium of local shopkeepers with no experience in building a railroad, the episode follows their efforts to build from west to east through the forbidding Sierra Nevada mountains with the help of Chinese labourers whilst