Zheng Lang, who had been away from his hometown for many years, suddenly received the news of his mother's death. He was forced to put down his work, say goodbye to his lover, and return to his hometown to deal with his future life. While dealing with his mother's belongings, he accidentally discovered the secrets that his mother had hidden for many years, and these secrets were actually related to who his father was. He searched hard bit by bit along the only clues, and finally revealed his life experience and learned about his mother's unforgettable love story.