This is the era of steam and steel, air guns and timid experiments with electricity. The Russian Empire is expanding its Asian possessions. Detective Anastasia, who only yesterday served as a field agent, is tasked with creating and leading a branch of the most mysterious unit of the Tsar's secret police - the Special Expedition - on new lands. The young cavalry officer Nikolai, who by the will of fate once got involved in the affairs of the Expedition, should become Anastasia’s main assistant in this difficult matter. After all, the new branch does not yet have either funds or extra employees... And its tasks are to investigate mysterious and inexplicable cases, which are unlikely to ever be declassified.