Tears of the Singers (Star Trek)

Captain Kirk and Enterprise join the Klingons to avert disaster in the Taygeta V system - where a time/space warp has swallowed a spaceship without trace. Spock suspects a link between the anomaly and the inhabitants of Taygeta, semi-aquatic creatures killed for the jewel-like tears secreted at the moment of death. But a mutinous Klingon officer threatens the vital mission, as a desperate Kirk and Spock race to save teh Taygetians, the Federation - and the entire universe!