"Thomasina" is a children's novel written by Paul Gallico, first published in 1957. The story revolves around a young girl named Mary and her beloved cat, Thomasina. When Thomasina falls ill and dies, Mary is heartbroken and learns about the deep bond between humans and their pets. The narrative explores themes of love, loss, and the cycle of life. Through magical realism, Thomasina's spirit returns to guide Mary, teaching her valuable lessons about grief and acceptance. The book highlights the importance of companionship and the impact pets have on our lives.