Shadows are at the heart of Book of Night, and they’re used as both psychological symbols and fabulist motifs. While the opening line positions shadows as playful companions—“Any child can be chased by their shadow” (1)—the first chapter pivots to explore how shadows have become a powerful and potentially dangerous magical artifact. Bar patrons display their cosmetically enhanced shadows: “One must have recently gotten her shadow altered, because she kept moving so the light would catch it and project her new self onto the wall. It had horns and wings, like a succubus” (5). In this way, shadows become a form of self-expression, like fashion choices or tattoos.

In addition, shadows become part of a lifestyle trend in which people address perceived faults through shadow manipulation. Through news articles, it’s implied that one can work with this shadow self to remove desires, negative habits, and even fear. This creates a practical and addictive way to shape one’s inner self. However, this method creates results that haven’t been earned or fully processed, ultimately making one even more vulnerable than before.

Finally, shadows also have a deeper meaning. Holly Black draws from Jungian psychology to present shadows as manifestations of the “shadow self,” or the hidden side of one’s inner nature.