Star Trek - Errand of Vengeance - Killing Blow

the long version

There are more than four hundred sagas aboard the Starship Enterprise, one for each of the unique men and women serving under the command of Capt. James T. Kirk. For years their personal adventures, their individual struggles and successes, have gone largely untold... until now. The U.S.S. Enterprise is patrolling the Klingon border when sensors detect a massive power source on a planet supposedly populated only by a race of primitive humanoids. Suspecting some sort of Klingon plot, Captain Kirk decides to investigate the matter personally, beaming down to the planet with Dr. McCoy and a team of security officers. But Kirk is in more danger than he knows. Among the landing party is Lt. Jon Anderson, a Klingon infiltrator on an undercover mission aboard the Enterprise. Anderson does not know if the Empire is at work on the unnamed planet, but if it is, then his duty demands that Kirk be stopped -- by all means necessary.