This Is How You Lose the Time War by Amal El-Mohtar & Max Gladstone

This Is How You Lose the Time War combines war via time travel (think Haldeman’s The Forever War), a love story between agents on opposite sides, and the epistolary novel (Les Liaisons dangereuses / Dangerous Liaisons, Griffin & Sabine). Exciting word play, and the intriguing letter delivery methods, made me look forward to the next epistle as much as the main characters did. —Dave