What does flyleaf- Cassie mean?

"Flyleaf" is a song by the band Flyleaf that features themes of longing, loss, and emotional struggle. Specifically, "Cassie" refers to a narrative about a girl named Cassie who faces profound challenges, reflecting deeper issues such as tragedy and resilience. The song captures the essence of her experiences and the impact they have on those around her, resonating with listeners who connect with its poignant message.