In this quote by Frederick Buechner, the author explores the concept of joy as a mysterious and unpredictable emotion that can manifest itself unexpectedly. The idea that joy can be found "even under the most unpromising circumstances" illustrates the resilience of the human spirit and its capacity to experience moments of happiness despite facing adversity. By mentioning joy having "tears in its eyes," Buechner suggests that joy can coexist with sorrow, highlighting the complexity of human emotions. Overall, the quote emphasizes the transformative power of joy and its ability to bring light into dark moments.