Xiao Bai has suffered from an incurable disease since childhood. After meeting a mysterious stranger who promised to save him, the young man tries to remember what connects them... In the distant past, young Xiao Bai lives in a foreign country in the emperor's palace, studies medicine and investigates mystical incidents. One day, strangers arrive in the country with overseas gifts. In exchange, the foreign prince wants to marry the princess and take her with him. On a snowy night, she comes to Xiao Bai and tells a story about the past. She continues to visit him, but suddenly Xiao Bai finds out that in fact the princess is bedridden and cannot wake up... Then who comes to him and what kind of illness is tormenting the girl’s soul?