These Eternal Works So Wondrous

Copenhagen, 1802. Watchmaker and goldsmith Niels Heidenreich struggles to get by in a city where the gap between rich and poor has become an abyss. Being a brilliant mathematician and engineer means little without funding, and his family teeters on the edge of starvation.
When a shadowy cabal of intellectuals offers him the opportunity of a lifetime, Niels has little choice but to accept. In exchange for financial security, he must steal two famous—and magical—golden horns from the Royal Chamber of Arts in Copenhagen.
After a successful heist, Niels learns that his new patrons wish to see the horns destroyed for the benefit of their supernatural masters. Now, he is opposed by his former allies, the Danish government, and extradimensional beings who wish to control humanity. To prevail, he must combine his mechanical skills with the powers of the horns and organize the poor and downtrodden in a rebellion against all masters, secular as well as supernatural.
Inspired by the true story of the Golden Horns of Gallehus comes a tale of wonder, the sublime, and the crisis of capitalism.