After almost ten years of bitter war, three great nations - the mysterious Protoss, the wild Zerg, and the Terrans, the descendants of humanity in the Sector - have concluded a truce, but this peace is shaky. When news of the sudden restoration of the once-burnt-to-the-ground planet becomes known, controversy flares up with renewed vigor. Neutrality gives way to hostility, and old enemies are accused of developing biological weapons to fuel the conflict. An expedition of Terran and Protoss soldiers and researchers is sent to explore the mysterious zerg planet and discover the plans of its inhabitants. But hidden in the lush vegetation are other creatures whose existence is shrouded in mystery, and it is they who, having gained freedom, are able to change the fate of the entire galaxy.