St. Petersburg, 1885. As tensions rise between the Russian Empire and the Great Britain, a mysterious mechanical flea is discovered in Emperor Alexander III’s palace. It's a sign: a British spy with cutting-edge engineering is operating in the capital. Secret police officer Ogarev teams up with Lefty, a genius – if slightly eccentric – inventor from the imperial arms factory. Together, they must stop the spy and protect the Empire from threats within and beyond.