This group of watercolor works presented in a four-square continuous form is the author's visual exploration of natural light and shadow and the poetic nature of time. The four pictures use "morning, dusk, day and night" as the narrative context, and adopt the traditional Chinese "four seasons make a year" time and space view to construct the framework. Through the unique transparency and fluidity of the watercolor medium, it captures the ever-changing light and shadow codes between heaven and earth. The picture is composed of the Chinese character "Hui", which implicitly conforms to the Taoist philosophical image of "Go around without end".