Dathan was a young Enaran Regressive whose forbidden romance with Korenna was relived by B'Elanna Torres through telepathic memories.
Dathan was a member of the Regressives, Enarans who rejected advanced technology in favor of a simpler life. His relationship with a young woman named Korenna was forbidden, as the Regressives were increasingly treated as outcasts by their society.
In Remember, B'Elanna Torres experienced Dathan through the memories of Korenna, now the elderly Jora Mirell. The memories revealed that the Regressives were rounded up and executed in a genocide that later generations were taught had never happened, and that Korenna's father had handed Dathan over to the authorities.