The inevitability that everyone mortal must age and die is a theme communicated through the unicorn and her interactions with mortals and the world around her. At the beginning of the book, the unicorn has no concept of time. She is immortal, and “had no idea of months and years and centuries, or even of seasons. It was always spring in her forest because she lived there” (2). Through the unicorn’s lens, the concept of growing old and dying is examined. This theme is introduced in the first chapter when the unicorn overhears the hunters’ conversation. One hunter remarks that his grandmother would weep when she recalled meeting a unicorn, but “she was a very old woman then, and cried at anything that reminded her of her youth” (4). The hunter’s grandmother crying as she looks back on her life is a foreign concept to the unicorn, who later wonders “what it must be like to grow old, and to cry” (31). The unicorn also often worries about her forest now that she has left. She knows that seasons will pass without her presence, and she “heard autumn beginning to shake the beech trees the very moment that she stepped out onto the road” (16).