Su Wen, a library administrator, wakes from his night shift to find his soul has transmigrated to the Tang Dynasty, where he is a bandit leader from the start.
Before he can catch his breath, soldiers come after him. Fortunately, Li Shimin saves him with a single word.
But just as he catches his breath, Li Shimin is attacked by assassins. Desperate to get in his good graces, Su Wen is forced to risk his life. Who could have guessed what would happen next...