Imagine Queen Elizabeth I never ruled. England and Scotland never unified. It's 1845 and the two countries are again at war. Mechanical genius Clara Lissing cares little for the war. She just wants to keep her five brothers safe. But when her youngest brother Tom enlists with the army, the happy family life she’s worked so hard to maintain starts to fracture. Clara goes to London to work with Duke Murgatroyd, building a device to end the fighting. Clara is determined to do her duty, help win the war and send everyone’s brothers home. But life in London brings with it the distracting presence of Gordy, Murgatroyd’s 18-year-old nephew. Gordy is a loose cog, twisting her clockwork life out of shape and making her think of things that aren’t work and duty. Then Clara discovers Murgatroyd’s secret plan for the army, the city, and England itself. With war reaching to the heart of London, Clara and Gordy must match duty with determination if they’re to save a nation.