After having a meal with Dr. Bashir, Lt. Dax is walking back to her quarters. She is followed by a group of aliens, who attempt to kidnap her. Dr. Bashir comes across the group while they are attempting to drag Dax away, and he manages to alert Commander Sisko that he and Dax were attacked and that she was taken away. The group of aliens take Dax on board their ship, having sabotaged and disabled Deep Space Nine's tractor beam using knowledge gained from their Cardassian allies. They nearly get away, but the Deep Space Nine crew is able to reestablish the tractor beam and prevent the ship from leaving.

The ship is brought back to the station, where Ilon Tandro, son of a famous military figure from Klaestron IV, accuses Dax — the Dax symbiont, then known as Curzon Dax — of murdering his father, and wants to punish Jadzia Dax for the crime. His claim is based on the fact that during a civil war a coded message informed the opposing side of his father's location, and of the people who knew the location, Curzon was the only one without an alibi.

Tandro tries to use the Federation-Klaestron treaty, which allows for extradition to get Commander Sisko to release Dax to their custody. But Sisko and Major Kira assert that since the station actually belongs to the Bajoran people, the Bajorans have jurisdiction. Since there's no formal treaty between Bajor and Klaestron, the Bajoran people (in the person of Major Kira) insist on holding an arbitration hearing. The hearing is held and Sisko raises the point that Jadzia and Curzon Dax are two different entities, sparking a lengthy debate. The arbiter suggests removing the Dax symbiont and leaving Jadzia behind, but Dr. Bashir points out that 93 hours after joining the host becomes biologically dependent on the symbiont, and to remove it would be fatal to the host after that point.

...
Wikipedia