Alix Harrow’s The Everlasting
Rereading this for book club! Turns out I remembered all the time travel/history stuff and totally forgot all the bits about war. Sorry, book club! I loved this just as much on a reread, and this is one of those books that benefits from rereading because you can see little hints before all the reveals. But it’s also just really moving, and about how hard and necessary it is to fight for a better world.