This Is How You Lose The Time War by Amal El-Mohtar and Max Gladstone

Rival agents in a war between technology and nature fall in love. Cyborg Red and fae-like Blue race up and down the “braid” of time sabotaging each others war efforts, and leaving hidden love notes that question the ceaseless fight, and if the women can trust enough to choose each others humanity over either’s cause. Poetic and perfectly succinct, this book has my heart and has brought me back to reread about once a year since it came out.