In her Legend trilogy — which included the novels Legend, Prodigy, and Champion — writer Marie Lu imagined a dystopian future in which, among other things, “Antarctica is home to a completely gamified society.” And while she went gaming free for her next couple books — the fantasy trilogy of The Young Elites, The Rose Society, and The Midnight Star — it’s an idea that apparently stuck with her. So much so that it’s become the basis of her new novel, Warcross (hardcover, digital), the first in a new duology.