Ruined City chronicles the struggles of a British aviation company called the United Airways in the aftermath of World War II. The story follows the company's new managing director, Peter Moran, as he tries to revive the struggling airline. Moran's efforts are hindered by various challenges, including labor strikes, financial troubles, and competition from other airlines. As Moran works to turn the company around, he also becomes involved in a romantic relationship with a woman named Mary. The novel explores themes of business ethics, loyalty, love, and the struggles of post-war society. Ultimately, Moran's determination and ingenuity help him to overcome the obstacles he faces and to bring success to the United Airways.