The U.S.S. Enterprise under the command of Captain James T. Kirk is en route to the extreme edge of the Alpha Quadrant, and to a region known as the Vara Nebula. Its mission: to investigate why science outpost Zeta Gibraltar is not answering all Federation hailing messages. When the Enterprise arrives, a scan shows no life forms in the science station. Kirk leads a landing party and quickly discovers the reason for the strange silence-signs of a violent firefight are everywhere. Zeta Gibraltar has been completely raided. Yet there are no bodies and the entire roster of station personnel is missing...