Star Trek the Next Generation - Legacy

The crew of the enterprise respond to a distress signal and attempt to rescue stranded crew members on the planet Tarkana IV, birthplace of Tasha Yar. When they encounter one of the warring factions, the coalition, it is soon revealed that among them is Tasha's Sister, Ishara. The crew and Data in particular are faced with having to reopen the wound Tasha's death left behind while getting to know this unique and different relative of hers who is trying to aid them in retrieving the captured crew.