"Invasive Procedures" is the 24th episode of the American syndicated science fiction television series Star Trek: Deep Space Nine. It is the fourth episode of the second season.

In this episode, a bitter unjoined Trill attempts to steal the Dax symbiont from Jadzia.

At a time when Deep Space Nine is all but empty, an unjoined Trill and his crew, a pair of hired Klingon mercenaries and a former prostitute named Mareel, overpower the crew of the station. Kira tries to take Mareel by surprise, but Mareel beats her in the fight. The Trill, Verad, once applied to be "joined" and was rejected; now he wants the Dax symbiont. After restraining the shapeshifting Constable Odo in a container and taking the rest of the crew hostage, he forces Dr. Bashir to transfer the symbiont into his body. Without her symbiont, Jadzia will die within hours.

Bashir has one of the Klingons assist him as he tries to save Jadzia's life. Meanwhile, Commander Sisko deals with Verad, who now has the memories of all the Dax hosts, including Curzon Dax, who was a very close friend and mentor to Sisko. He implores the Trill to set things right, but he sees that Verad intends to let Jadzia die. Meanwhile, Mareel, who Verad had befriended early in life, begins to realize how much the man has changed since he received the symbiont, and begins to think the joining may have been a bad idea. However, she remains loyal to him.

Quark, who is responsible for Verad and his crew boarding the station, pretends to be injured and thereby provides Bashir with the opportunity to sedate one of the Klingons. He then cracks the lock on the container holding Odo. Once Verad realizes what has happened, he heads for his ship, taking Kira as a hostage.

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