An ensign who died after the Doctor chose to save Harry Kim instead, a decision whose guilt led the crew to erase his memories of her.
Ahni Jetal is an ensign whose story is uncovered in Latent Image. During an attack on an away mission, she and Harry Kim were both critically wounded, and the Doctor could save only one of them. He operated on Kim, and Jetal died on the operating table.
Afterwards, the Doctor's belief that his friendship with Kim had swayed his choice created a conflict in his ethical programming, and Janeway had the memories deleted. When the Doctor rediscovers images of Jetal, the breakdown returns. Seven of Nine argues that he deserves the chance to work through his guilt, and Janeway lets him keep the memories.