On the Double Ninth Festival of that year, he met her. From then on, there was a lingering relationship... Many years later, he asked her desolately: "Do you regret it?" After thinking for a while, she said: "I regretted it." Indeed, everything is in the past. But, he still remembered everything about her. He remembered the lifelong promise he made to her on that misty morning on the North Canal. He remembered that on that snowy day, she was dressed in red, but she cried hoarsely in the urn of Xuanwumen. He still remembered that in those war-torn years, after the explosion tragedy, she said to him affectionately: Tianqi, I won't leave. She is a mysterious woman. Who is she swearing to in the urn city on a starlit and moonlit night? Whose life was taken by that cold shot on Luban Road? In the sea breeze of Deep Water Bay, to whom is she telling secrets that have been sealed for many years? In front of a tombstone in Qingshan Liyuan, whose past was she reminiscing with tears? Who was that ascetic who made her cry so hard under the stupa of Lingshan Temple? At the cold Shiliupu Pier, the man's wailing echoed through the sky. Whose pain did it awaken? Such a woman suddenly disappeared without a trace on an autumn day full of bitter red flowers. When she left, she wore on her chest a heart promised to her by the man she loved. However, many years later, the heart that once disappeared from the world suddenly reappeared on a beach in California. Now, a young woman wearing that heart is smiling slowly and softly at the man she loves on the beach under the setting sun...