The stills of Butterfly on the Shoulder (12) were invaded by the devil and their lives were dying. His fiancee Baby made a contract with a mysterious creature, and she became a butterfly herself. In exchange, Guo Yan recovered. Guo Yan magically recovered his health, only to find that his lover was gone, and he became depressed and withdrawn. The baby who has become a butterfly can only watch him get depressed day by day, but there is nothing he can do. Soon, Guo Yan got the attention of her neighbor Brandon and Yang Lin, a female journalist who came to the island from the metropolis. A new love has sprouted between Guo Yan and Yang Lin, which makes the baby's heart full of bitterness. In the last year before the baby can change from a butterfly to a human, an epidemic broke out on the island, and the situation was very serious. At the critical moment, the baby found himself able to find the key formula of the antidote studied by Guo Yan. So this fragile butterfly began a dangerous journey. Even though her wings were broken, she continued to fly. Can the scarred baby bring back the medicine formula that Guo Yan needs to fly back to him? Who is the only true love in Guo Yan's heart? When become a butterfly's three-year sacrifice is over, will the baby change back to human form to find out?