Lieutenant Rhea Young is serving on the Enterprise under Captain Picard. She is strong willed with a sunny disposition and she has a crush on the stoic Klingon, Worf.
At the end of 2374, Jadzia Dax is killed by Dukat aboard Deep Space nine. The Dax symbiont is rushed aboard the fastest ship available: the USS Intrepid. The Intrepid never makes it to Trill.
In mid 2375, Liom Dax arrives on Deep Space Nine with brand new ensign's pips, a black belt in Betazoid Lowchan Fighting, orders to serve as a low-ranking security officer, and a head full of memories that don't completely make sense.