New series. Dan Snow, Anita Rani and Ade Adepitan go behind the scenes to reveal the hidden systems and armies of people running four of the planet's greatest cities. The first edition focuses on Hong Kong, with Ade heading into the high rises to find people living in tiny spaces no larger than a cupboard, Dan discovering how it is adapting to life since it was handed back to China in 1997 and Anita learning about the city's many traditions.