Shera's Resurgence

Science officer Shera is on her way back to her home planet when they receive a distress signal from the small planet L'Khan. She offers to take a team down to investigate. Captain Chevanto is devastated when the team returns without Shera. Not only is she his first officer, his number one, but without her knowledge, he has fallen in love with her. They search for her for days but cannot find her.
Who has kidnapped Shera? And why?