The Silicoids are a growing threat from beyond the frontier. Launching waves of crystalline drones, they ravage colonies all along the border of the Empire. Earth has been forced to ally with her enemies against this mysterious alien menace. Scouts have located a forward base of the freakish creatures, who plot to annihilate all meat-based lifeforms. Earth assembles a joint task force with legions of Rigellian bears, Mogwa battlecruisers, and Saurian troops. Together, they strike as one against Crystal World. After annoying every superior in his chain of command, James McGill is the first to be deployed on the unexplored planet. His to establish a beachhead on this strange, hostile ground. Surrounded and cut off, his troops fight to the bitter end against creatures made of earth, stone, and jewels. Find out what happens next in CRYSTAL WORLD, the thrilling 20th book of the Undying Mercenaries series. With millions of copies sold, USA Today Bestselling author B. V. Larson is the king of modern military science fiction.