Star Trek: 10 MORE Characters Permanently Displaced In Time

Can Lt. Tasha Yar ever catch a break?

In the Prime Universe, she is senselessly killed by the creature Armus, thrown across a desolate space, sapped of life. Despite Dr. Crusher's best efforts, she expires on the operating table. This is truly an ignoble end for a fine officer.

The accidental arrival of the Enterprise-C in the future offers her legacy another shot at the wheel. In this changed timeline, she never died on Vagra II, and still serves as the Chief Tactical Officer on the Enterprise-D. Once it becomes clear that the older ship must return to where it came from, and she herself becomes aware of her counterpart's fate, she requests permission for a transfer. If she is to die, let her death have meaning.

She does indeed travel back to the Battle Of Narendra III, affording the Enterprise-C a few extra moments, thus impressing the Klingons, and restoring the timeline.

However.

She is taken captive by the Romulans and brought back to Romulus for interrogation. Once this is complete, she was set to be executed, only for an officer to take a shine to her. She was effectively acquired as his concubine, and bore a child to him - Sela. Yar never gave up hope of getting home, and one night tried to escape with her daughter. Sela, alas, was happy where she was, and called out to her father.

Yar, having earned her hero status, was executed in the past - setting the stage for major events to follow.