It's 1914, in the China of another Earth. On this Earth, the Boxer Rebellion of 1900 was the Boxer War, and ended with a complete defeat of the Chinese and the occupation of China by the Eight Nation Alliance. On this Earth, steam-powered dirigibles prowl the skies, and steam-powered mechas are a part of every advanced nation's army.
On this Earth, in its Shanghai, the head British spy is Anthony Hall, an aging widower. Assisted by his local aide-de-camp, Li, Hall runs the British spies of the middle of China, carrying out schemes against the Russians and the Japanese, the two main enemies of the United Kingdom. Hall's best friend is Evelyn Featherstone, a half-Chinese freelance spy.
Their lives irrevocably change when one of Hall's best agents is murdered, sending Hall on a long chase to discover the murderer, and when Featherstone is blackmails a business executive into betraying a secret. This brings Featherstone to the attention of the Japanese government, which hires her to carry out a very special job.
Hall and Featherstone find their professional lives intersecting and their professional goals clashing, and against the backdrop of impending war they must find a way to survive what the Fates throw at them while also preserving their friendship.
