In this 1876 'Mission Impossible' tale of intrigue set in Russia, a traitor has inspired the fierce Feofar Khan to invade Siberia and foment a rebellion. A sinister plot to assassinate the Czar's brother, the Grand Duke, is discovered but all telegraph lines have been cut. Only one of the Czar's courier's is qualified to handle the dangerous and arduous mission to warn the Siberian Governor General of the impending invasion, Michael Strogoff.