When a distress calls goes out from a Federation outpost near the Klingon border the USS Enterprise, under the command of Captain Christopher Pike, responds. Starbase 18 lies in ruins, and there are no survivors. Nor is there any clue to who is responsible for the attack, until the Enterprise's brilliant science officer, Lieutenant Spock, discovers a unique energy signature -- one he believes is Klingon. There have been unsubstantiated reports that the Klingon Empire has made a technological leap forward and created a cloaking device -- code-named Black Snow Seven -- which can shield their ships from even the most advanced sensors. The destruction of Starbase 18 and Spock's subsequent detecting of the mysterious signal are proof that they have succeeded.

Now Captain Pike is charged with a vital mission -- to gain the cooperation of the Orions, a proud and powerful race who were once a major force in the sector, and who have no love for the Klingons -- or for the Federation. The Federation needs them as allies, and a distress call from an Orion ship provides the perfect opportunity for Captain Pike to go to their aid and thus foster good relations. But the Orion vessel lies in disputed space long claimed by the Klingon Empire, and crossing it could be the spark that ignites an interstellar war.