Sisko has a dinner party, at which Jadzia plays a tune on a musical instrument, despite insisting that neither she nor any of the Dax symbiont's previous hosts had any musical ability. Shortly afterward she begins having violent mood swings and experiencing strange visions. She, Sisko, and Dr. Bashir go to the Trill homeworld, but their efforts to discover what is happening to her are stymied by the doctors there.
- Bunny-Ears Lawyer: Timor, the guardian of the symbionts, is extremely good at his job but comes across as Cloud Cuckoolander otherwise.
- Canon Discontinuity: Getting hijacked by Verad apparently doesn't merit as a "Traumatic event" for the Dax Symbiont.
- Malevolent Masked Man: Jadzia has recurring hallucinations of one. It's her memories of being Joran trying to resurface.
- Screw the Rules, I'm Doing What's Right!: Sisko doesn't care much about Trill politics, but he will save Jadzia's life, even if he has to effectively blackmail the Symbiosis Commission to do it.
- Sherlock Scan: Timor can tell that something's wrong with Jadzia at a glance, and figures out the rest by simply laying a hand on the implanted Dax Symbiont.
- Unperson: The Trill government tries to purge all mention of Joran from their records and Dax's memory, causing the problem in the first place.
- Well-Intentioned Extremist: The Symbiosis Commission have to deceive the public about the percentage of join-worthy Trill to keep the Symbiont species from becoming nothing but a commodity.