Necessary Evil ( episode ) An attempt on Quark ' s life re - opens a five - year - old murder investigation . Summary . Teaser . On Bajor , a lavishly dressed Bajoran woman named Vaatrik Pallra stands next to her window on a dark and stormy night . Quark is seated on a nearby couch as the two of them reminisce about the Cardassian Occupation . The woman reiterates that she did not kill her husband , although Constable Odo was convinced she did . It is clear Quark does not believe the woman ' s claim , but he does not care . She hires the Ferengi to retrieve a box , the contents of which are not revealed , hidden in her husband ' s former shop aboard what is now Deep Space 9 . Assuring her it will take a day or two at most , Quark leaves . After he is gone , a Bajoran man steps out from the shadows . Act One . On DS9 , as Odo goes about his daily routine , he narrates a log . Later that evening , Quark and Rom approach the former chemist ' s shop ( now a storage area ) cautiously . Quark says he can break through the lock in twenty - five seconds , but Rom is able to do it in ten ; he has used a desealing rod to break into the store room at Quark ' s on occasion while Quark was away . Although Quark accuses his brother of being a thief , Rom denies it . Once they are inside , Rom reveals that he has magnasite drop , which can instantly burn off the wall panel ; Rom has had to use them to open Quark ' s latinum floor vault to store extra profits on good business days . Rom has been hoping that his ingenuity would finally earn his brother ' s trust , but the older Ferengi tells him never to touch anything in the bar again . Quark takes a small box from behind the wall panel and he and Rom take it back to the bar . There Quark opens it to reveal a list of eight Bajoran names . Curious to find what they are , he tells Rom to fetch an imager before he reseals the box . However , while Rom is gone , the Bajoran man who was with Quark ' s employer emerges from the shadows , armed . The Ferengi immediately knows who sent the other man ; their mutual employer knew Quark could not resist taking a peek . The man shoots Quark with a compressed tetryon beam and takes off with the list . Rom then comes back with the imager , sees his brother lying on the ground , and starts screaming for help . Act Two . Doctor Bashir is now kneeling over Quark ' s unconscious body , attempting to resuscitate him as Odo , Commander Sisko and Major Kira look on . Quark is taken to the infirmary , and Kira goes off to secure outgoing vessels as Sisko and Odo turn their attention to Rom . While the younger Ferengi seems upset by the apparent loss of his brother , Odo suspects Rom of killing Quark for ownership of the bar . Rom is unable to conceal his elation at the thought of finally getting the bar , but then realizes that that makes him a suspect . Sisko ( apparently playing " good cop " ) speaks up in Rom ' s defense , saying that his son is good friends with Sisko ' s , and asks Rom , as a friend , to share anything he knows that might be helpful . Rom comes across with the truth about the list , and Quark ' s mysterious employer on Bajor . Rom then leads Odo to the ship ' s store , mentioning that the list was hidden during the Occupation , when the room was the chemist ' s shop . Odo looks at him sharply , and he flashes back five years as the doors open . " Odo , dressed in a nondescript civilian outfit , enters the chemist ' s shop , where Dukat , the Prefect of Bajor and the commander of Terok Nor , is seated behind a desk in someone else ' s office , in complete control and enjoying it . Dukat introduces himself to Odo and says that the owner of the shop , Vaatrik , has been found murdered . The standard Cardassian form of " justice " in such an event is to execute ten random Bajorans as an example to the real murderer . But Dukat , claiming that he prefers to be more merciful on this occasion , would rather find the real murderer . Odo has something of a reputation for integrity and is known for breaking up disputes between the Bajorans , so Dukat asks him to conduct the inquiry – since Bajoran witnesses and suspects are hardly likely to be open to a Cardassian officer . Odo is resistant to the idea of working for the Cardassians , but agrees for the sake of justice : finding the guilty party is preferable to decimating ten innocent Bajorans . " " Dukat introduces Odo to the prime witness , the victim ' s wife , Pallra , who hasn ' t shed a tear since her husband was murdered . Pallra says right away that she knows who killed her husband : a young woman with whom he was having an affair . The woman is still on the station , and she points out a young Kira having a solitary meal on the Promenade . " The flashback ends as Kira approaches Odo . The attempt on Quark ' s life , and the mention of the list , has brought Vaatrik ' s murder to both their minds . Act Three . In his office , Odo is attempting to get Rom ' s mind off of the bar , and the two of them review the events of the night before in an attempt to jog Rom ' s memory . Although the Ferengi is unable to remember any of the complete names , he believes the first one started with " Ches ' so " . Odo gives the name to Kira , who goes to investigate as Odo enters another flashback . " Odo approaches Kira in an attempt to seem casual ; however , his behavior and lack of experience make it all too obvious that he is a security officer . Kira denies having had an affair with Vaatrik ; in fact , she was transferred to the station from the surface after hitting a supervisor who made sexual advances to her . When Odo asks her for an alibi , Kira says she was in the bar , trying to find work . Odo is a little frustrated at her reticence , and insists that he is not on anyone ' s side , especially not Dukat ' s . She rejoins that he will have to pick a side ( Cardassian or Bajoran ) eventually . " On Bajor , Odo interviews Mrs . Vaatrik in her home , which , in sharp contrast to the time of Quark ' s visit , is now brightly lit and sumptuously decorated . She claims to be ignorant of any list , or of the attempt on Quark ' s life . Odo asks whether the name " Ches ' so " means anything to her , she says no . As he is leaving he compliments her on the elegance of her home , then mentions that records show her power had recently been cut off for lack of payments , yet now she is living well again . With a smile , she states that she has received gifts of money from an acquaintance , whose identity she can ' t reveal . Odo leaves and a distressed look crosses her face . Act Four . Dr . Bashir is unsure if Quark will live . Major Kira stops by the Infirmary to tell Odo that she thinks she has identified the " Ches ' so " he is looking for : a mining engineer named Ches ' sarro Seeto , who traveled to the station frequently during the Occupation , and has since been very active for charities benefiting Bajoran war orphans . The bad news is , Ches ' sarro is dead – he drowned in a pond at his home the night before . Odo realizes that Mrs . Vaatrik had Ches ' sarro killed as soon as he mentioned the name " Ches ' so " to her . Realizing that Mrs . Vaatrik knows from him that Quark is still alive , he stations a security guard in the infirmary around the clock . Looking at the still - unconscious Quark , Odo enters another flashback . " As he enters Quark ' s and found the Ferengi , Odo once again tries to be casual and discreet , and once again is unable to hide his role and connection to Dukat . When Odo asks him to confirm Kira ' s alibi , Quark insinuates that Kira was performing a sexual favor for him the night before , as an added " incentive " for him to hire her . But from what he gathered earlier , Odo knows Kira would not do this . Confronted with the truth , Quark admits that Kira paid him to provide her with an alibi . " Odo finds Commander Sisko and Lieutenant Dax sitting in Quark ' s , and informs them that he has reconstructed the list from Mrs . Vaatrik ' s communications logs and bank records : eight people , who had no previous contact with her , suddenly began talking to her extensively after the list was stolen , and each of them has transferred 100 , 000 Bajoran lita s into her bank account . The three of them reach the same conclusion : the men on the list were collaborating with the Cardassians during the Occupation , and emerged from the Occupation very rich men ; with the list , Mrs . Vaatrik has been blackmail ing them . Odo admits that he doesn ' t have enough evidence to charge her with a crime , but gets permission from Sisko to bring her in for questioning . Meanwhile , the man who tried to kill Quark looks on intently . Act Five . In his office , Odo flashes back again . " In the security office , Kira admits that she lied about her alibi , but swears that she didn ' t kill Vaatrik . Odo demands to know where she was , then , and she admits that she is a member of the Bajoran Underground , and was part of a team that planted a bomb in the ore processing section of the station . She begs him not to expose her , saying that she will be executed by the Cardassians . Just then , Dukat enters , demanding to know whether or not Kira is guilty . Realizing that he has to choose a side , Odo does not expose Kira , but simply informs Dukat that he is satisfied she did not commit the murder , and she is free to go . " Mrs . Vaatrik ' s assassin enters the infirmary with a bouquet of flower s and uses them as a cover to stab the guard Odo has posted there . Approaching Quark ' s body , he turns off the Ferengi ' s life support monitor and then starts to smother him with a pillow . Rom enters the room , and , seeing the scene , begins ( hilariously ) screaming at the top of his lungs . The assassin throws Rom aside and tries to run , but is stopped at the door to the infirmary by Odo and his deputies . Odo restrains the assassin and summons Bashir to the infirmary . Rom is still screaming , and Odo tells him he can stop , he has heroically saved his brother ' s life . Rom appears pleased for a moment , only to realize he has lost possession of the bar , causing him to start screaming again . On the infirmary bed , Quark has just regained consciousness and gives a small but triumphant smile . In the brig , Mrs . Vaatrik is brought to view the assassin , and calmly states that she ' s never seen him before . Odo and Kira say that her communications records and bank transfer statements tell a different story . Vaatrik says she wants her advocate , and Odo locks her in a cell next to the assassin ' s while she is waiting . Mrs . Vaatrik defiantly says that , no matter what else Odo thinks she may have done , she didn ' t kill her husband and Odo can ' t prove that she did . To Kira ' s surprise , Odo replies , " I know . " Outside in the security office , Odo confronts Kira with what he has figured out : Vaatrik himself must have been a collaborator , or else he wouldn ' t have had a list of names hidden in his office . Dukat could not risk exposing his other contacts on Bajor by investigating Vaatrik ' s murder himself , which is why he conscripted Odo to do it . Also he knows that Vaatrik ' s wife wouldn ' t have killed him , since he was the one keeping her in luxury . All this means that the people with the strongest reason to want him dead would have been the Underground . Kira admits that another group of resistance fighters sabotaged the ore processor , while she was sent to Vaatrik ' s shop . She was not sent to kill him , but to find the list , knowing that Vaatrik was Dukat ' s liaison with his network of collaborators . She was searching the shop when Vaatrik surprised her , forcing her to kill him . Odo asks her why she didn ' t tell him the truth , even after the Cardassians left and it became clear that he was not working for them . She said she couldn ' t bring herself to tell him the truth , for fear it would create a schism between them . He tells her that this incident may not affect their friendship , but can find no answer when she asks him if he ' ll ever be able to trust her in the same way again . Memorable quotes . " " She sent you , didn ' t she ? " " " " She knew you wouldn ' t be able to resist taking a look . Sorry . " " " " Yeah , me too . " " ( gets shot ) " " Help ! Somebody help ! My brother ' s been killed ! " " " " I ' ve had my eye on you for a long time , Rom . You ' re not as stupid as you look . " " " " I am , too ! " " " " Rom , as a friend , if you know anything that might be useful , I think you should tell us . " " " " . . . There was a list . The man who shot my brother stole a list . " " " " What kind of list ? " " " " Of names . Eight Bajoran names . It was in this box we . . . we found . " " " " Found ? " " " " In a manner of speaking . " " " ( growling ) " You . . . " " " " I really oughta be getting back to my bar . " " " " He ' s not dead yet , Rom ! " " " " They ' re not keeping him alive by artificial means , are they ? My brother wouldn ' t want that . " " " " No , he ' s clinging to life all on his own . " " " " Typical . " " " " All right , let ' s try again . Close your eyes , take a deep breath . . . clear your mind of anything in it . . . if there ' s anything there . . . breathe . . . breathe . . . now , what do you see ? " " " " The bar . " " " " Yes ? " " " " With my name on it ! " " " " You ' re not planning on leaving the station soon ? " " " " If I were , would you have the Cardassians stop me ? " " " " Yes . " " " " Then I ' m not planning on leaving the station soon . " " " " I ' m looking for the proprietor of this establishment . " " " " Does he owe you money ? " " " " No . " " " " Are you here to arrest him ? " " " " No . " " " " Then you ' ve found him . Quark , at your service . " " " " I misjudged you , major . You were a better liar than I gave you credit for . " " " " You were working for the Cardassians . " " " " I haven ' t been for more than a year . You ' ve had all that time to tell me the truth . " " " " I tried to tell you the truth , a hundred times . . . What you think of me matters a lot . I was afraid . . . " " " " That it might affect our friendship ? " " " Kira nods . " " " Maybe it doesn ' t have to . " " " " Will you ever be able to trust me the same way again ? " " " " It ' s over Rom ! Over ! You ' re a hero . " " " " I am ? " " " " You saved your brother ' s life . " " Links and references . References . advocate ; agent ; anti - grav lift ; apostrophe ; autopsy ; Bajor ; Bajoran ; Bajoran Center for Science ; Bajoran underground ; Basotile ; blackmail ; Cardassian s ; Cardassian ale ; Cardassian Empire ; Cardassian groat ; Cardassian High Command ; Central Bank of Bajor ; chemist ' s shop ; chemical s ; Ches ' sarro Seeto ; chocolate ; collaborator ; compressed tetryon beam weapon ; constable ; cortical stimulator ; cortolin ; desealer ; desealing rod ; duranium ; epidermis ; eulogy ; Federation ; Ferengi ; floor plate ; Gamma Quadrant ; gul ; holosuite ; Hadar ; homicide ; imager ; investigator ; ; latinum ; lita ; magnasite ; medical examiner ; Meldrar I ; Mora Pol ; neck trick , Cardassian ; Nog ; Occupation of Bajor ; ore processing center ; power company ; pulsatel lockseal ; Promenade ; Pyrellian ginger tea ; Quark ' s ; replicator ; Rules of Acquisition ; ship ' s store ; shock ; soft drink ; storeroom ; sub - nucleonic device ; supervisor ; Terok Nor ; tetryon ; thoracic cavity ; vault ; vial