From the Back Cover
When the
Enterprise responds to a distress signal from a Federation freighter, it leads them to Turkana IV, birth planet of their late comrade Tasha Yar. The freighter crew has been forced down onto the planet and the men are being held underground by the Alliance, one of two warring factions fighting for control of the planet.
The rival faction, the Coalition, contacts the Enterprise and assigns Ishara Yar (Beth Toussaint), Tasha's sister, to help them find the captured men. Once on the Enterprise, Ishara proves to have extensive knowledge of how to penetrate the Alliance's defenses.
As the crew prepares for the rescue mission, Ishara befriends Data (Brent Spiner) and tells him she would like to leave Turkana IV and attend the Starfleet Academy. She has begun to gain the trust of the crew, but has she really given up her allegiance to the Coalition?