Did you believe in time travel or time slip? Well… Inspector Ahn Shin Hye is 30-years old and an ace in their unit. She is assigned in the cold case department that chases serial killers. She’ll meet a man who loves to tease her. While chasing a serial killer, she will be entangled to a mysterious event. After falling in Han river, she will wake up in a strange situation… She became the queen of Joseon dynasty?! As the new member of cold case department in Seoul district. Lee Sun Jin finds Ahn Shin Hye as an interesting woman. He teases her on their first case together. After falling in Han river, he wakes up and became the king of Joseon?! How can these two opposite personalities solve cases in that timeline? As they realizes that the most powerful seats are like sitting in a throne made of thorns. Will love blooms even political struggles is in the picture?