Several generations before the events of the sci-fi classic Ender's Game, the alien antagonists attacked Earth. The Formics, as these insectoids are called, initially descended in the First Formic War trilogy (Earth Unaware, Earth Afire and Earth Awakens). Forty million people died when a single Formic scout ship ravaged China. Mazer Rackham (a central character in Ender's Game) and a handful of other humans managed to destroy that ship, only to discover a full fleet of warships were en route to the solar system.
With less than five years to prepare for an impossible second war, the nations of Earth have ceded global political control to a Hegemon and military control to a Strategos and Polemarch. Earth's efforts are bent on survival, with characters from the First Formic War series caught up in the struggle. Mazor Rackham is testing experimental weaponry when he faces a court martial for standing up to a corrupt officer. Lem Jukes, son of the Hegemon and new CEO of his father's former company, deals with impossible technical challenges. Victor Delgado is out in the Kuiper Belt on a mining ship, and Bingwen, in the vein of future Ender Wiggin, is training as a child soldier/commander. The Formic attack is already coming too soon, but, as The Swarm unfolds, these characters discover it might be much closer than they'd feared.
Orson Scott Card and Aaron Johnston (also co-author of the First Formic War trilogy) deliver another dose of satisfying genre action. The Swarm stands on its own merits, though it's recommended to read at least the original Ender's Game first. --Tobias Mutter, freelance reviewer