There are more than four hundred crew members on a Federation starship, and each of the men and women who serve under Captain James T. Kirk has his or her own story. Each has a different part to play in the saga of the USS Enterprise -- and the role of one in particular stands out from the rest...

The USS Enterprise is patrolling the Klingon border when sensors detect a massive power source on a planet supposedly without advanced technology. Suspecting a Klingon plot, Kirk beams down to investigate in person, accompanied only by Dr McCoy and a small security team. But Kirk is in danger from an unexpected quarter, for the landing party includes Lieutenant Jon Anderson -- and Anderson is a Klingon agent on an undercover mission, briefed to report on the Enterprise and its crew. Anderson does not know if the Klingon Empire is at work on the unnamed planet, but if it is, then his duty requires that Kirk be stopped -- by any means necessary.