10 Utterly Devastating Star Trek Endings That Came Out Of Nowhere

Sito Jaxa was introduced in The First Duty. In that outing, she is merely one of the team when Wesley Crusher is called in front of an inquiry into Joshua Albert's death. That episode focuses heavily on Wesley and Nick Locarno, so it was something of a surprise when Jaxa returned in Lower Decks.

The young Bajoran officer was shocked that she was posted to the Enterprise, never truly believing that she would get a fair shot at a career. It was Worf who first helped her believe in her abilities and what she could bring to the ship, so much so that she respectfully stood up to Captain Picard. 

The revelation that everyone wanted her to succeed warmed hearts, though this came with a terrible cost. Her mission - accompany a Cardassian double agent back home, then attempt to escape - aimed to bring about the end of hostilities between the two powers. The audience had every reason to believe that she would survive.

Picard's announcement to the crew, informing them of Jaxa's death, was a shocking and devastating moment. We had seen her firmly established as a vital part of the ship, with friends, colleagues, and more rooting for her. It was one of the earliest examples of Star Trek offering a perspective outside of the main cast of characters, and for it to end in such a fashion, it showed a confidence in both the character and her actor, Shannon Fill, which paid off in dividends.