Lu Xiao, a modern security professional, is transporting equipment when he unexpectedly travels back in time to an ancient dynasty along with his armored vehicle. Appearing out of nowhere in the imperial palace, he is immediately mistaken for an assassin. Using his modern firearms and vehicle-mounted equipment, he takes a princess hostage to protect himself and navigates the dangers of the imperial court and battlefield. When a massive enemy army from the north invades, he puts aside his personal grudges and heads to the battlefield, defeating powerful foes with advanced tactics and saving countless civilians. But after achieving fame and success, undercurrents begin to stir among the powerful aristocratic families at court, and a conspiracy to seize the throne quietly unfolds. An even more perilous political predicament awaits him.