The Alternate ( episode ) The Bajoran scientist who used to be Odo ' s teacher arrives with evidence of others of Odo ' s kind . Summary . Teaser . In his bar , Quark is trying to sell pieces of Plegg to another Ferengi when Odo walks in and comes up to Quark . The other Ferengi leaves upon hearing Quark ' s asking price , and Odo takes out latinum as if to buy some of the remains , before informing Quark that he wants to buy parts of Plegg , but that is impossible because Plegg is still alive . As they are discussing this , Dr . Mora Pol enters the bar and calls out to Odo . As Quark starts to talk to Dr . Mora , Odo leaves in disgust , with Dr . Mora walking with him . They head to the Replimat , where Dr . Mora hints that he may have a clue as to Odo ' s origins . Act One . Benjamin Sisko is reading a PADD in his quarters when Jake tries to discreetly leave to meet Nog . Sisko asks Jake about his homework , and upon hearing that it is done , tells Jake he can ' t leave because he should be listening to Klingon opera to appreciate their culture . In frustration , Jake asks his father when was the last time he listened to Klingon opera . Sisko informs Jake that it was when he was his son ' s age , and then suggests that Jake invite Nog over and they can listen to the Klingon opera together . Jake walks off in frustration as Odo enters . Odo requests the use of a runabout for investigation of a planet in the Gamma Quadrant , where DNA similar to Odo ' s had been found . Jadzia joins Odo , Dr . Mora , and a Bajoran scientist , Dr . Weld on the runabout , and Dr . Mora encourages Odo to tell Jadzia the story of when he was in the lab , but Dr . Mora then repeatedly interrupts Odo to correct him . The four people beam down to the planet , L - S VI , and begin to scan the surrounding area . They come upon an artifact with unrecognizable letters on it . Jadzia suggests taking the artifact back to the station to let the computers there decipher it . As they are engaged in looking at the artifact , Dr . Weld comes across a lifeform which has similar DNA to Odo . The silicate - based creature is placed in a container , and the artifact is transported up to the runabout . As soon as it leaves the surface of the planet the ground begins to shake . Dr . Mora starts to cough , and then falls to the ground . Soon after , Jadzia and Weld do the same , and only Odo is left standing , when the computer locks onto their combadge s and transports them back to the runabout . Act Two . In the infirmary on the station Dr . Bashir is caring for the two Bajorans and Jadzia , though he will need more time to understand what happened . Odo wasn ' t affected by the gas that paralyzed the others as he has no respiratory system , so he joins Miles O ' Brien in studying the silicate - based creature that was found on the planet . Along the way , Sisko walks with Odo , sensing he is worried about Mora as a son would see his father ill . Odo appreciates the thought , but doesn ' t see Mora as a father figure . O ' Brien states that the creature keeps changing , and that he ' s put a level 5 security field on it . It ' s been frequently reproducing and undergoing a . He observes the artifact they brought back for a second , then leaves . That night , Sisko is sleeping when Major Kira wakes him up and asks him to come down to the science lab . He enters the lab , and sees that the lab has been trashed . The case that the lifeform was in has been broken apart . Act Three . The crew looks for signs of what has happened , while Odo sets up a scan for the missing lifeform , and the station goes to yellow alert . O ' Brien notes that the lifeform might have gone through the ventilation . Jadzia enters the science lab and Odo leaves to talk to Dr . Mora . There , Mora attempts to leave sickbay to help find the creature , but Odo convinces him to stay . As O ' Brien crawls through the ventilation duct in search of the lifeform , he is informed by Sisko there was a malfunction in the lab ' s security cameras and a temporary increase in heat . He suggests a lifeform that feeds off the computer ' s power , but there should have been an increase detected . Then , he hears something , and follows the sound . He comes across a structural breach , and when putting his hand up to touch the structure it breaks , pouring down some kind of liquid . He identifies it as the missing lifeform , and states that it is now dead . Dr . Bashir studies the lifeform , and determines that it needed more carbon dioxide to survive . As he is in the infirmary , he hears a noise coming from the ceiling . He is unable to find anything , but as he resumes his work a tentacle comes up from behind and grabs him . He struggles , it lets go , then he uses a laser scalpel to cut the creature . The lifeform retreats back through the ceiling vent , and Bashir calls security down to the infirmary . Act Four . After a team arrives , Bashir explains to them what he has seen , but he ' s not too sure about it . However , he did agree it was warm and so Odo suggests looking for RF energy and the same power fluctuations they saw in the lab . Dax finds organic residue traces , giving more analysis to do . Sisko puts the station on red alert and Odo suggests to close the Promenade . As Odo and Mora walk away from the infirmary , Mora remarks at Odo ' s handling of his job . He ' s quite proud , and talks about the similarities between police work and the scientific method like a parent recognizing a child following their footsteps . Odo just says he was doing his job , but also that he hadn ' t thought of his approach to his work like that . Odo and Mora arrive at the lab , and Jadzia reports no luck translating the symbols or with the residue . Jadzia runs a cross - tabulation analysis , and , during , Mora talks to Dax about him . Dax says he ' s private , but invaluable on the station . Mora clearly regrets the bad parting they had previously , and is pleased he is integrating into society . The analysis completes and they find that the lifeform found on the planet and the one that attacked Dr . Bashir in the infirmary don ' t have enough similarities to be the same lifeform . Dr . Mora has her run a lengthy analysis on the new sample , but he already knows what it is . Mora goes to Odo ' s office to tell him he recognizes the organic sample as being from Odo himself . Act Five . Dr . Mora confronts Odo with the likelihood that it was probably Odo himself who committed the trashing of the science lab and the attack on Dr . Bashir during his regeneration period . Odo proposes the gas affected him somehow , but Dr . Mora thinks it ' s gone on a long time . Dr . Mora attempts to convince Odo to return to the scientific center with him , since he has the experience , but Odo refuses . He says he doesn ' t trust Mora , which Mora resents . As they are arguing , Odo hits a security panel and he starts to change into something else . Dr . Mora flees from security . Dr . Mora arrives at Ops as the station crew attempt to find out why the power in security has just failed . He explains that Odo is the creature , and that this metamorphosis is probably a reaction to the gas that was encountered on the planet . Dr . Mora volunteers to be bait to attract the creature that was Odo into a trap . Mora waits on the Promenade , along with Sisko , Kira , Bashir , and station security personnel . The creature comes out and into the force field waiting for it . Dr . Mora watches in distress as the creature slams itself into the force field again and again , realizing then how Odo must have felt during his time at the center – a prisoner . The force field drops and the creature morphs into Odo and falls to the ground . Mora rushes over to him . In the infirmary , Odo is back to normal again , and Bashir informs him that the gas has been purged from his system . Odo apologizes to Dr . Mora for attacking him , and Mora apologizes for not seeing sooner how Odo felt . Mora says he would like to be a small part of Odo ' s life on the station and visit , and Odo accepts . Memorable quotes . " " I am merely a businessman . It would take an orator with the skills of the late , great Plegg himself to sing the praises of the late , great Plegg . " " " " Humanoid death rituals are an interest of mine . " " " " Death rituals ? " " " " Everybody needs a hobby . " " " " Doctor Bashir gave you permission to be up and about ? " " " " Doctor Bashir wouldn ' t listen to me and hid my clothes so I wouldn ' t leave . I had to sneak out to my quarters in a hospital gown that wouldn ' t close in the back . " " " " Feel like getting a raktajino before we call it a night ? " " " " My replicator or yours ? " " " " Constable " ? " " " It ' s a nickname that I barely tolerate . " " " " It ' s an expression of affection that you find difficult to accept . " " " " I prescribe rest , because it ' s hard for a doctor to go wrong with that one . " " Links and references . References . Alpha Quadrant ; Bajor ; Bajoran s ; Bajoran Institute of Science ; Bajoran science probe ; Bajoran sector ; Bajoran wormhole ; Board of Ministers ; carbon - based lifeform ; carbon dioxide ; cellular structure ; Changeling ; confined to quarters ; conduit seal ; constable ; Deka tea ; DNA chain ; DNA pattern ; energy field s ; entrepreneur ; family reunion ; Federation ; Ferengi ; Ferengi death ritual ; Ferengi Seal of Dismemberment ; Friday ; Gamma Quadrant ; holosuite ; homework ; hospital gown ; intruder alert ; Khosla II ; kill setting ; Klingon ; Klingon opera ; Krokan petri beaker ; label ; L - S VI ; latinum ; letter of authenticity ; ; Nog ; nucleotide ; ; Plegg ; polarity ; Promenade ; Quark ' s ; RF energy ; raktajino ; red alert ; replicator ; Replimat ; runabout ; scientific method ; security camera ; silicate ; ; stun setting ; synchronous orbit ; tentacle ; tornado ; trace element ; tricorder ; viscosity ; yellow alert