The Passenger ( episode ) An alien criminal , attempting to prolong his life , hides his consciousness inside the mind of a station crew member . Summary . Teaser . Major Kira and Doctor Bashir are returning from a medical mission in the runabout . Kira was reluctantly impressed by Bashir ' s competence , after he found a vital clue in a woman whom she dismissed as deceased . Bashir appears to accept such praise as no more than his due , and Kira is about to tell him off for his arrogance , when they receive a distress call from the " Reyab " , a Kobliad transport ship . They beam aboard to find that the ship ' s systems have been disabled by a fire raging on board . Kira looks for fire safety gear , and Bashir goes to the nearest crewperson , a Kobliad female named Ty Kajada . He asks her if anyone else is on board , and she says the pilot is dead . But Bashir reads another life form behind a locked door , and Kajada warns for him not to open it , the man is a prisoner who started the fire in an attempt to escape . Over her protests , Bashir overrides the door lock and finds a dying Kobliad male , Rao Vantika . Kira comes back and extinguishes the fire , preparing all four of them for emergency transport back to the runabout . Before she can energize , Vantika seizes Bashir by the throat with an iron grip and pulls him close . As Kira tries to pry his hand loose , Vantika growls , " " make me live " " , before expiring . Act One . Back on Deep Space 9 , Bashir revives Kajada in the infirmary . When she awakes , her thoughts go immediately to her prisoner . Bashir says the man is dead , but Kajada insists on examining his body herself . Bashir , a little insulted , assures her that Vantika is quite dead . She retorts that she has tracked Vantika , a multiple murderer , for over twenty years , during which he has faked his death more times than she can count , and more than a few medical " experts " have been fooled . After scanning Vantika ' s retinas to confirm that he is brain dead , Kajada shocks Bashir by coolly stabbing the corpse in the chest with a trocar . She asks Bashir to autopsy the body and confirm its identity with DNA records , and to scan her ship for anomalous life readings . Shaken , Bashir agrees . In Quark ' s , Quark delivers a drink with unctuous good wishes to Jadzia Dax , while Odo scornfully asks what he thinks his chances are with a woman like her . Quark retorts that nothing ventured , nothing gained , and not everyone in the galaxy is comfortable being as lonely and miserable as Odo . Odo is then put out to receive a visitor , Starfleet Security officer Lieutenant Primmin , who says they have been assigned to work together . In Ops , Bashir reports that every test he has run confirms that the dead Kobliad is Rao Vantika , and that he is indisputably dead . Kajada has warned that Vantika was on his way to Deep Space Nine when she captured him , and Sisko and Dax connects it with a shipment of deuridium ore scheduled to arrive at the station from the Gamma Quadrant . The Kobliads are a dying species , and need deuridium to stabilize their cell structures . Even with new deposits discovered in the Gamma Quadrant , the demand far outstrips the supply , so it makes sense that Vantika would want to steal a supply for himself . Bashir says Kajada still isn ' t convinced Vantika is dead , so Sisko agrees to her request to scan her ship . He is also concerned with unearthing any preparations or accomplices Vantika had on the station in preparation for the hijack . In conference with Primmin , Sisko quickly disabuses him of his belief that the station ' s security needs an " overhaul " to conform with Starfleet Security regulations ; Odo has his own way of doing things , and Sisko has found that way to be effective , and best suited to the unique situations aboard the station . Sisko encourages Primmin to be a little more flexible , as he could actually learn something from " The Constable . " With difficulty , Odo and Primmin begin working together , reviewing the security arrangements for the deuridium shipment . When Odo tries to access the computer , however , he is surprised to find that everything in the active memory banks has been accessed and then purged . He believes this is impossible , but Kajada appears in his office and says that Vantika has done exactly the same thing before on Rigel VII . Act Two . In Ops , Sisko and his crew confer , with Kajada and Primmin present . Kajada says that Vantika usually pulls this sabotage trick by planting a subspace shunt in a nonessential system that would be overlooked by security checks . Odo concedes it is an elegant trick : rather than try to get past security programs guarding a particular file , a criminal simply performs a dump of the whole memory , which has not or cannot be guarded against . When a scan of the station detects an anomalous device planted , Odo ( and Primmin ) both order a security patrol to retrieve it . During these instructions , Kajada constantly speaks as though Vantika has done these things himself , but Sisko remains skeptical , and asks her whether it is more likely that some accomplice of Vantika is the one responsible . Kajada delivers an impassioned brief of Vantika ' s criminal history : the man is obsessed with ensuring his own survival ; he has prolonged his life in myriad ways , and many of his crimes have been committed in the course of experiments , or thefts of cutting - edge research , to discover even more ways . Kajada assures them all that Vantika wouldn ' t have started the fire on board the ship unless he had a plan for living through it ; she doesn ' t know what that plan was , but the sabotage aboard the station is enough to convince her that it succeeded . Impressed by her arguments , Sisko instructs the crew to assume for the time being that Vantika is alive , until Bashir receives DNA confirmation from Kobliad Security of the corpse ' s identity . Odo asks to have a word with Sisko in his office . Odo begins to complain about Primmin ' s presence , but Sisko already knows what he ' ll say . To Odo it is a professional insult , not to mention an annoyance , to have another security chief on the station . Sisko immediately says he likes Odo since he knows where he stands , but he reminds Odo that Starfleet has its own interests on the station , which makes Primmin a fact of life that Odo will have to deal with . Sisko says he has already encouraged Primmin to work with Odo , but Odo isn ' t satisifed . He wants to know who ' s in charge , and Sisko says : Odo . Trying not to look too pleased , Odo admits , " I can live with that , " and departs . In Dax ' s lab , she reports to Sisko that someone tried to break into the cargo hold of the " Reyab " after it was docked at Deep Space Nine . What they could have been looking for , Dax reports , is an isolinear chip she found , containing a " map " of the humanoid brain . In Quark ' s Bar , Quark is collecting his " tips " ( dropped money ) from the floor of the upper level , when someone seizes him from behind and whispers in his ear , asking him whether he ' s made the preparations for the deuridium shipment – hiring a group of mercenaries . Baffled , Quark says that he has done so , but he was told Vantika was dead . The voice whispers , " " almost , but not quite , " " then releases Quark and retreats into the shadows . Act Three . Bashir calls Kajada into the infirmary and triumphantly shows her the final results of the DNA comparison ; every conceivable test has been run , and confirms that the Kobliad in the morgue is dead , and that he is Rao Vantika . To his amazement , Kajada still isn ' t convinced . Dax calls Bashir into her lab and shows him Vantika ' s computer models . She theorizes that Vantika was developing a means of transferring his consciousness into another ' s brain . Bashir says that such a thing is theoretically possible , and if Vantika succeeded , then his most likely " host " is Kajada , the nearest available Kobliad . They present their theory to Sisko , who isn ' t convinced . Why would Kajada be warning them so if Vantika was controlling her ? Bashir explains that , according to their theory , Vantika is only controlling Kajada part of the time ; the rest of the time , he ' s simply " along for the ride , " and Kajada isn ' t even aware of his presence . Sisko asks for proof , and Dax says that they can ' t know what to look for until they have a better idea how Vantika accomplished the transfer . Odo is in his office when Kajada storms in , protesting that he ' s revoked her security access and is refusing to answer her questions about the precautions for the deuridium shipment . He says he is just being extra cautious , and she storms out . Suspecting that Quark may be assisting Vantika , Kajada spies on him from the upper level of the bar after closing time . She finds him meeting with the mercenaries he summoned , including Durg . Suddenly , they look up when they hear a scream , and see Kajada , hanging from the balcony rail . Before any of them can react , she loses her grip and plummets to the deck . Act Four . Kajada lies in a coma in the infirmary , but not before saying she was pushed by Vantika . Bashir reports to Sisko that he cannot examine her more closely until she regains consciousness . Sisko theorizes that Kajada may have tried to kill herself after realizing she was carrying Vantika around with her . In the morgue , Sisko finds Dax taking samples from under Vantika ' s fingernails . She says she thinks she has found his transfer method : a biocoded message imprinted onto a , that allows a message to be transmitted along a humanoid ' s nervous system directly to the brain . She found models of the glial cells on Vantika ' s data chip . Since the most effective means of transfer would be to inject the cells directly into the victim ' s skin , but there were no needles or hyposprays in Vantika ' s belongings . Examining the tissue from under his nails , Dax finds a microscopic electric generator , to " fire " the message along the nervous system . Vantika hid the device there , just to give himself a last - ditch escape . In the docking ring , Quark leads the three mercenaries to one of the runabout pads , explaining that their mysterious employer managed to access one , and is waiting for them on board . The door opens , and there is Dr . Bashir . Quark backpedals , stammering that they took a wrong turn . But " Bashir " steps forward , smiles coldly , and says , in a voice quite unlike his own , that on the contrary , he has been expecting them . Act Five . Dax enters the infirmary , calling for Bashir . He does not answer . She asks the computer to locate him , and it answers " the Infirmary . " She finds his combadge left on a counter . Odo meets with Kira ' s team and is surprised to find that Primmin is not working alongside them as agreed . When Odo finds Primmin , the lieutenant explains that he decided to take a hint from Odo ' s methods , and tried to think like Vantika . Doing so has led him to discover a second subspace shunt hidden in the waste extraction system . Impressed , Odo says that the device , if left in place , would have disabled the station for close to an hour . As the deuridium cargo ship comes through the wormhole , a runabout leaves the station , unscheduled , to escort it to the station . In Ops , the crew discover that Doctor Bashir is missing , and that it was his access codes that enabled the launch of the runabout . On the cargo ship , the three mercenaries beam aboard and kill the bridge crew , before signalling Vantika / Bashir that it ' s safe to board . Sending two of the mercenaries to secure the rest of the ship , Vantika orders the shields raised and to lay in a new course . Before the ship can engage , the station locks a tractor beam on them . Vantika is frustrated , because he thought he ' d sabotaged them . Sisko hails the ship , and Vantika introduces himself from Bashir ' s body . He demands that the tractor beam be removed , or else he ' ll engage the warp drive , tearing the ship to pieces – killing Bashir and the remaining crew and spreading deuridium ( a hazardous material ) all over the system . When the mercenary on the bridge refuses to commit suicide , Vantika shoots him dead with his phaser . He gives Sisko one minute to decide , then cuts off the transmission . Sisko asks for suggestions . The ship ' s shields are raised , and any attack to overwhelm them would risk breaching the ship ' s hull . Dax comes up with a way of sending an electromagnetic pulse along the tractor beam , where it will resonate off the shields and cause an energy field inside the ship that will disrupt Vantika ' s hold over Bashir . It is successful , for long enough for Sisko to get through to a very confused Bashir , who lowers the ship ' s shields , and let him be beamed to Ops . As Rao tries to seize control of him again , Sisko stuns him with a phaser , and they take him to Dax ' s lab . With a specially programmed transporter , she removes Vantika ' s signature glial cells and transfers them to a small containment field . Scanning the unconscious Bashir , Dax pronounces him " clear , " and revives him . Waking up with a groan , Bashir ' s first words are to complain of a splitting headache . A short time later , Sisko , Bashir , Dax , and a recovered Kajada regard the containment field in Dax ' s lab . Kajada apologizes to Bashir for his ordeal , while Bashir feels that they all owe her an apology for not taking her warnings about Vantika more seriously . Bashir confesses that he doesn ' t remember any of what Vantika made him do , and feels humiliated for not being able to stop it . Sisko assures him that no one holds him responsible . Kajada asks Sisko to formally return custody of " the prisoner " to her . As soon as he agrees , Kajada draws her phaser and disintegrates the container , wiping out the last traces of Vantika , then walks out without another word . Sisko ' s expression indicate he is a little unsettled by her cold - blooded " execution " of Vantika , and even more unsettled when Dax and Bashir show no reaction at all . Memorable quotes . " " Ah , yes , well . . . tricorders , very accurate with living people , not so accurate with dead ones . We learned that in first year medical school . " " " " Make . . . me . . . live ! " " " " If you want my opinion . . . " " " " Actually , I don ' t . " " " " Three persons were on your ship . Two bodies are in our morgue . Unless the ghost of Vantika is . . . " " " " Don ' t patronize me , Commander ! " " " " What kind of fool are you ? ! " " " " My own special variety . " " " " I ' m sure almost everyone knows about the shipment by now . Odo was probably making sure that Quark knows we know he knows . " " " " I ' ve been asking myself , why would anyone induct a bioelectric charge into a glial cell ? " " " " A question I have always wondered about . " " " " I want to speak with Dr . Bashir ! " " " " Unfortunately , he ' s . . . not available at the moment . " " " " You ' re deluding yourself . " " " " There ' s nothing wrong with a good delusion , I sell them upstairs to dozens of people every day . " " " " I ' m watching you , Quark . " " " " And I ' m watching you , Jadzia . " " Links and references . References . allergic reaction ; alpha wave ; alpha - wave inducer ; " Antares " - class ; anti - gravity generator ; authorization access code ; auto - destruct system ; automatic fire suppression ; autopsy ; bailiwick ; Bajoran s ; Bajoran system ; Bajoran wormhole ; biobed ; bioelectrical pulse ; bio - regenerative research ; black market ; body ; brain ; brain scan ; Cardassian ; Cardassian freighter ; cargo bay ; cell structure ; cellular longevity ; central power linkage ; cerebral cortex scan ; clone ; coin ; combadge ; computer ; computer chip ; computer memory ; consciousness ; cryogenics ; day ; deep space ; Deep Space 9 levels ; defense array ; deuridium ; distress signal ; distribution amplifier ; DNA ; DNA reference scan ; docking bay ; docking ring ; drug ; electromagnetic pulse ; emergency unit ; EM field ; examination ; Federation ; Ferengi ; fiddle ; fingernail ; fingerprint ; fire ; fire extinguisher ; freighter ; Gamma Quadrant ; ghost ; glial cell ; glial scan ; glove ; handshake ; headache ; healer ; helm ; high security penitentiary ; hijacking ; holding cell ; hour ; hull breach ; Humanoid ; hypospray ; impulse ; infirmary ; jail ; jewelry ; joint operation ; jurisdiction ; Kobliad ; Kobliad homeworld ; Kobliad pilot ; Kobliad Security ; Kobliad transport ship ; lab ; life support ; lighting control ; logic ; long range sensor ; maneuvering subsystem ; manual override ; map ; medical supervisor ; medical school ; medical supervisor ; medical tricorder ; mercenary ; microcontainment field ; microscope ; microscopic generator ; Milky Way Galaxy ; minute ; morgue ; morning ; needle ; nervous system ; neural pattern ; nitrogen ; " Norkova " , " Norkova " crewmembers ; O² ; paralysis ; parasitic infection ; petri dish ; phaser ; pilot ; power waveguide outlet ; preliminary examination ; priority one ; Promenade ; pulmonary trauma ; raktajino ; raktajino machine ; rejuvenation drug ; replicator ; respiratory failure ; retinal imaging scan ; retinal pattern ; retinal scanner ; " Reyab " ; Rigel VII ; ; runabout ; scan ; scanner ; scapular node ; scientist ; security alert yellow ; security code ; security file ; security lockout ; security office ; security sweep ; shield generator ; shields ; skin ; soldier of fortune ; Starfleet Academy ; Starfleet Command ; Starfleet Security ; starship ; stasis ; stasis room ; stowaway ; structural integrity field ; subspace crossover link ; subspace crossover shunt ; subspace shunt ; suicide ; synaptic field ; synaptic pattern ; synaptic pattern displacement ; temperature control ; tractor beam ; transplant ; transporter lock ; unnamed medical tools ; Vantika ' s victims ; virtual positron imaging scan ; Vener VII ; visual cortex ; Vulcan s ; warp ; waste reclamation system ; week ; wing ; year Deleted scene references . launch pad ; security clearance