This Is How You Lose the Time War is a beautifully written romance between two women across the timeline of the world. I'm not even a huge sci-fi person, but this book really sold me on time travel. The writing, while admittedly not for everyone, I thought was gorgeous and very well done. The world building focuses less on the overall aspects of the war and more on each individual scene and letter, which allows you to connect with the characters and their romance. I could not put this down, and I wish it had been longer than approximately 200 pages. I loved following Blue and Red around throughout various settings and time periods, and their letters to each other were beautifully written. The end had me on the edge of my seat, the suspense was fantastically written, and the resolution was so creative that I had to go back and reread the last 50 pages. It's a wonderful book.