Time ' s Arrow , Part II ( episode ) Trapped in 19th century San Francisco , the crew of the " Enterprise " must locate Data and prevent his death while stopping the Devidians from destroying Earth ' s history . ( " Season premiere " ) Summary . Teaser . The year is 1893 and Samuel Clemens is walking down a street in San Francisco , California with a young reporter in tow while Clemens discusses time travel . He expresses his belief that there are people from the future , " right here in San Francisco . " Their discussion ends when Clemens sees Lt . Cmdr . Data emerge from a building nearby and begins walking up the street . As he follows Data , they unknowingly pass a woman walking with a man who is carrying a walking stick with the head of a snake on it . Act One . Commander Riker and Dr . Crusher are in a makeshift morgue somewhere in San Francisco in 1893 . Crusher is dressed in a black period dress with an elaborately decorated hat while Riker is dressed as a police officer . Riker mentions that the morgue is the location of all the cholera victims . Crusher expresses her surprise at so many people dying of cholera because it " just isn ' t that virulent . " She scans a body with her medical tricorder and finds that the victim ' s entire nervous system has been depleted of electro - chemical energy . She determines that a number of the victims died because their neural energy was drained , not because of cholera . Later , in a rented apartment , Crusher explains her findings to Captain Picard , Lt . Cmdr . La Forge and Counselor Troi . Riker adds that they found triolic activity in the bodies that had to have come from the Devidian s . La Forge suggests that they may be able to create an " alien alarm system " to alert them to the presence of the Devidians . He adds that he has been unsuccessful in contacting Data yet , though his tricorder is broadcasting on all frequencies that Data can sense . They are interrupted by a knock at the door and a shrill voice shouting for " Mister Pickerd . " Mrs . Carmichael enters demanding the weekly rent . She is upset because it is one o ' clock on Thursday and the rent is due at one o ' clock on Wednesday . Picard explains that he and his theater troupe are rehearsing for their upcoming production of " A Midsummer Night ' s Dream " and that they have played to packed houses in London , Paris , and Milan . He promises her the rent in full with a bonus but she tells him no , she ' ll have her rent " " tomorrow , or you ' ll be out performing on the street ! " " At the Hotel Brian , the bellboy , Jack , lets Clemens into Data ' s room . Clemens says he is looking for a letter of intent , but he is really just snooping . Jack takes the opportunity to ask Clemens if he ' ll write his life ' s story . Clemens tells him , " " No one is more qualified to write your story than you are . " " Clemens encourages him to follow his dreams and go to Alaska . Jack agrees and vows to do it and reveals his full name to be Jack London . He leaves Clemens alone in Data ' s room . Clemens walks over to a device on Data ' s desk and removes a piece of it . The device stops functioning just as he hears a noise from the hall . He quickly hides in the wardrobe closet . Data and Guinan enter the room . She explains that Data will not be able to get into the cavern under the city because the only entrance is in the middle of the Presidio on an Army base . Data tells her he has full confidence in her persuasive abilities . She finally agrees to help him gain entrance when he notices that the transceiver assembly has been removed from his device . He explains that without it , he will be unable to track the time shifts . Guinan says that she believes Clemens is behind the missing piece because he has been stalking her lately . Data tells her that , if so , he must be warned that prolonged exposure to the piece would be toxic . An unexpected noise , quite like a transceiver assembly being dropped inside a closet , leads them to the wardrobe where they discover Clemens hiding . Act Two . Data picks up the transceiver from the floor of the wardrobe as Clemens wipes his hands with a handkerchief . Clemens emerges from the closet as Guinan says , " " Shame on you ! " " Clemens is instantly indignant and directs shame at both Data and Guinan . He says his friend Ches Whitley in the county assayer ' s office has told him that Data claims to be a geological engineer interested in mining operations in the 1850s . He goes on to tell Data many of the other places he ' s visited recently . Clemens then asks about the device on the desk and whether it has anything to do with time shifts . Data explains that a time shift is a gearing device he has invented for the horseless carriage . Clemens is agitated at the answer and tells Data that he knows he ' s come to " " this century , and brought your infernal technology with you " " and that he ' s up to no good . Guinan interrupts and tells Clemens to mind his own business and leave . Clemens rebuts that it is his business and the business of all Humanity to stop them from whatever they are doing , then he leaves . In a ward of the Sisters of Hope Infirmary , Picard is reassembling a gas lamp when he is questioned by a doctor . Picard explains that he is replacing the burner with a safer version in case of an earthquake . The doctor dismisses him and tells his nurse ( a disguised Dr . Crusher with tricorder in hand ) that he is leaving . Crusher hides the device in her apron and the doctor leaves . Across the room , La Forge says he can see an afterimage of triolic waves by a bed . Crusher says a man just died in that bed the previous night . Troi offers that another patient was complaining about a strange doctor and nurse near that bed and perhaps they ' re still in the building . La Forge and Troi leave as Crusher tends to a coughing patient . The device that Picard planted on the lamp begins to flash and Crusher ' s tricorder makes an alarm noise . She turns to see a doctor in a tall hat and a nurse in a dark cape standing nearby . She activates her combadge and approaches them . She asks the doctor if he needs any help and remarks that his cane is interesting . The nurse aims her bag at Crusher just as Riker , La Forge and Picard enter with Troi close behind . La Forge grabs the cane and knocks the Devidian down on a bed . He gets back up and Riker shoots him with a phaser . He is unaffected and turns to his companion and they vanish . Just then , Data ' s device records the time shift . He consults a map and hurriedly leaves the room . Back in the infirmary , a police officer arrives and asks Riker what is going on . Riker is unable to convince him to let them leave and the officer confiscates the cane from La Forge . Riker remarks that he has the " utmost respect for the law " just as he knocks the policeman to the ground and takes the cane . They leave the hospital and see Data driving a carriage toward them . He stops and they all get into the carriage . Three police officers run toward them as the galloping horses take them away . Act Three . Back in the apartment , La Forge supposes that if he tunes a phaser to the approximate frequency of triolic waves and hit the cane with a field burst it might respond . He tries it and the head of the cane transforms into the ophidian the Devidians used to create the gateway . Tiny bursts of energy like bolts of lightning emanate from the snake which then transforms back into a cane . La Forge says they look like minute distortions in the space time continuum . Data remarks that the Devidians must have some way of concentrating the distortion . La Forge observes that anything that could focus them would produce high levels of triolic waves like in the cavern where Data ' s head was found . Data informs them that he has found that cavern . An unexpected knock at the door and Mrs . Carmichael ' s voice intoning , " " Mr . Pickerd ! " " interrupts them and everyone scatters to pre - arranged places . Troi answers the door as the others read from their Shakespeare playbooks . Picard tells Mrs . Carmichael that they need someone to read a part . He shows her where to read and she does so very stiltedly . Picard stops her and tells her how unique her reading was . " " Really ? " " she asks . Picard nods and announces that they have found their Titania . He tells her they start rehearsals tomorrow and kisses both her cheeks . She giggles . Guinan is in Data ' s room waiting . Data returns and she announces that she has found a way to get into the mine shaft under the Presidio . Picard walks in behind Data . She stops speaking and stares . He returns her gaze and removes his hat . She asks if he knows her . He replies , " " Very well . " " She then asks , " " Do I know you ? " " Picard answers , " " Not yet , but you will . " " Outside the Sisters of Hope Infirmary , the reporter is finishing a conversation with the police officer who was struck by Riker . The reporter turns and walks alone down the street and meets Clemens who says hello . He tells the reporter that he heard two people vanished into thin air in the infirmary . The reporter tells him yes , and that he was told a band of outlaws set off an explosion in the hospital and then escaped . Clemens asks what they looked like and learns that the carriage they escaped in was driven by an albino . Clemens exclaims , " " They ' ve come from the future . My God ! It ' s an invasion ! " " and he quickly hails a passing carriage . The reporter asks him if he has any proof . Clemens promises to meet him at 4 : 30 with a story that will make his career . He gets into the carriage and says , " " Take me to the Presidio , driver , and don ' t spare the whip ! " " In the cavern under the Presidio , Riker notes that there triolic waves are just as high as those on Devidia II , but that he doesn ' t see any control mechanism . La Forge observes crystalline fractures in the rock wall with his VISOR . He says the entire cavern has been configured to focus the space time distortions like a lens , but he doesn ' t know if it will work with phaser power . Picard says they have to try . " " An event I most certainly would enjoy witnessing . " " Says Clemens as he descends the stair into the cavern . He holds a cigar in one hand and a revolver in the other . He then says he plans to take them all to the authorities . Data tells him it is imperative that they finish their mission . Clemens tells him to move and suspects that " " even time travelers are vulnerable to the Colt . 45 . Let ' s go , " " he says , glancing at his pocket watch , " " I don ' t want to be late . " " Suddenly , next to Troi , the Devidians appear and snatch away the cane . Data grabs the cane and knocks the male to the ground . The cane emits many sparks and flashes before exploding . Everyone in the cavern is knocked from their feet and Data ' s head tumbles into the dirt , sparks dancing around his lifeless eyes . Picard sits up and sees the portal back to Devidia II open . The male Devidian checks his female companion and runs through the opening . He is followed by Riker , La Forge , Troi and Crusher . Just as the portal begins to collapse , Clemens dives through , leaving Picard and Guinan alone in the cavern . Act Four . Back on Devidia II in the 24th century , Riker is surprised to find Clemens is with them . Clemens asks , " " Where are we ? And when ? " " Riker explains , and adds that he ' s not supposed to be there . Clemens claims he has the same right to be in their time as they had to be in his . Riker tells him that his disappearance would be problematic . Lieutenant Worf ' s voice over the communicator interrupts them and Riker tells him to stand by to transport five . La Forge calls Riker ' s attention to Data ' s headless body lying on the cavern floor still clutching the cane . Riker tells Worf to transport six and they beam up to the " Enterprise " . In the transporter room of the " Enterprise " , Riker calls for security to escort Clemens just as Worf arrives . Clemens is startled when he first sees him and exclaims , " a werewolf . " La Forge tells Crusher to have Data ' s body taken to the science lab where he ' ll try to reattach the head they have . Troi offers to escort Clemens to his quarters . They walk out together as Clemens asks if they ' ve ever run into Halley ' s Comet . In the San Francisco cavern , Guinan awakens in Picard ' s arms . She asks him why he stayed behind and he tells her that he had to make sure she was all right . He adds that she is far too important to him to let anything happen to her . Picard explains that in the future , their relationship will go far beyond mere friendship . Guinan laments that she ' ll have to wait 500 years and that she won ' t be able to tell him about it when they eventually meet . She notices Data ' s head and Picard comments that it is history fulfilling itself . In Ten Forward , Riker is angrily pushing Guinan for answers to how to get Picard back . She refuses to tell him for fear it would change history . Riker leaves in frustration . Troi has changed into her regular uniform and is walking the corridors with Clemens who is craving a hand - rolled Havana cigar . He says that he ' s not impressed with the future with all its technology and the loss of simple pleasures like gentlemen opening doors for ladies . He speculates that they have terrible weapons on the ship and that military conquest is a way of life . He seems amused at seeing a Bolian walk by them . They enter a turbolift and go to deck 36 . On the way , Troi explains that they live in a peaceful Federation and the Bolian isn ' t a captive , but rather one of the thousands of species they ' ve encountered . Clemens supposes that they are privileged and that they probably ignore the poor . Troi tells him that poverty was eliminated on Earth a long time ago , along with many other ills of Human civilization . Clemens , caught somewhere between sarcasm and incredulity , says he comes from a time where inequality , prejudice , and the ruthless pursuit of power and wealth are the norm for Human behavior , " " and you ' re telling me that isn ' t how it is anymore ? " " Smiling serenely , Troi responds yes . Clemens ponders her words and says that perhaps this future is worth giving up cigars for after all . They exit the turbolift and enter the science lab where La Forge has reattached Data ' s head to his body . He explains that Data ' s activating units won ' t initialize . Clemens is pleased to find his watch on a nearby table and La Forge says that after 500 years it probably won ' t work either . Clemens goes over to Data and apologizes for misjudging him , as he has misjudged many things . Back on Earth , the female Devidian awakens . Her arms and head sporadically flicker with blue light , revealing her true form . She asks Picard why they interfered with them . Picard says they are hunters and are killing Humans , they " had " to stop them . He tells her that the " Enterprise " is going to destroy their transport site on Devidia II . The Devidian tells him that they ' ll only amplify the time distortion and annihilate Earth . She flickers with blue light and disappears . Act Five . In the observation lounge , Riker announces that he is going back for Picard . Worf says they should destroy the cavern immediately to stop the temporal incursions to Earth . Troi agrees and Riker concedes . He asks to be alerted when the photon torpedo es are ready . In the science lab , La Forge is working with the computer to revive Data . The computer says the reload circuits are initializing , but La Forge still can ' t understand why he can ' t get Data to reactivate . He asks the computer to run a diagnostic on the input polarizer s and finds there is only intermittent contact there . He goes over and opens a small panel on the back of Data ' s head and finds an iron filing in the circuitry . He wonders how it could have gotten there . In the cavern on Earth in 1893 , Picard goes over to Data ' s head and picks it up . He opens the back panel on his head and looks around the cavern . He finds an iron filing and begins to do something to the circuitry under the panel . On the bridge , Worf informs Riker that the torpedoes are armed . Riker says to fire when ready . Worf replies that they will be ready to fire in only one minute . La Forge , in the science lab , has the computer run another diagnostic on the input polarizers . They are now functioning properly and he activates Data ' s positronic brain and turns him on using the switch on his back . Data revives , turns to La Forge and says , " " Torpedoes . . . Phasing . . . Alien . . . " " He reaches back and adjusts something on the back of his head and tells La Forge he is processing a binary message entered into his static memory by Captain Picard . He then says it is imperative that they do not fire on the caverns . La Forge contacts Riker and tells him to hold his fire . Later , on the bridge , Data is back in uniform and tells Dr . Crusher , Riker and La Forge that the message from Picard isn ' t entirely clear . He says Picard was concerned that the phase differential of the torpedoes might produce catastrophic effects . He says they need to modify the torpedoes so the force of the explosion is re - phased into the alien ' s time continuum . La Forge says he can fit the torpedoes with phase discriminator s but it will take a couple hours . Riker decides he now has time to go back and get the captain . Crusher tells him that the phaser will probably work , but the rift will only be stable enough for one person . Clemens and Troi enter and overhear Crusher . Clemens says he should be the one to go , so he and Picard can return to their proper places in time . Riker agrees and orders La Forge to brief Clemens on what he needs to know . Clemens shakes Data ' s hand warmly and thanks him for starting him off on " " the greatest adventure a man ' s ever had ! " " Guinan , in the Earth cavern , tells Picard she is thirsty . He says he ' ll go for help when Clemens enters , with the cane in hand . He explains that , " " This thing put me down in the middle of Market Street . It took forever to get here . " " On the bridge , Worf tells Riker that the reconfigured torpedoes are ready . Riker says they ' ll wait five minutes , then fire . In the cavern , Clemens explains to Picard that La Forge got his message and that a frequency setting of . 047 on the phaser will activate the ophidian . Picard asks Clemens to get help for Guinan and to settle the bill at Mrs . Carmichael ' s boarding house . He agrees to take care of both matters . Picard thanks Clemens , and explains that he wishes he could have gotten to know him better . Clemens points out that his personality is written in his books . Picard goes to Guinan and she says , " " I ' ll see you in 500 years , Picard . " " He replies , " " And I ' ll see you . . . in a few minutes . " " They part . Data reports to Riker that he is picking up massive triolic wave activity on the surface , but there are no Human life sign s or temporal distortions . Riker orders Worf to fire torpedoes . Just as the torpedoes are away , Data detects Human life signs on the planet . In the Devidian cavern , Picard sits up and witnesses the Devidians flashing into and out of view just as Chief O ' Brien beams him out . Worf reports to Riker that the target has been destroyed . Riker orders the ensign to lay in a course for the nearest starbase at warp 6 . Picard enters Ten Forward to see Guinan . They both look upon each other with warmth . In the Earth cavern , Guinan is carried away on a stretcher and Clemens assures her she ' ll be fine . He stops and picks up his watch and goes to put it in his pocket , then he remembers . He places the watch on the floor of the cavern not far from Data ' s head and leaves the cavern . Both the watch and the head wait on the cavern ' s floor for history to repeat itself . . . Memorable quotes . " " I just want you to know that I have the utmost respect for the law . " " " " Young man , I have a maxim that I have always lived by : no one is more qualified to write your story than you are . " " " " Shame on you , Mr . Clemens ! Shame ! " " " " Werewolf ! " " " " Do you know me ? " " " Very " well . " " " " Do I know you ? " " " " Not yet , but you will . " " " " I suspect that even time travelers are vulnerable to the Colt . 45 . " " " " Where are we . . . and " when " ? " " " " This is the 24th century , we ' re on Devidia II and you ' re not supposed to be here . " " " " The disappearance of Mark Twain , one of the most noted literary writers of the 19th century . . . " " " " Thank you ! " " " " That ' s " not " supposed to happen . " " " " I only took advantage of an irresistible opportunity , as any good writer would . " " " " You know an awful lot about me . " " " " Believe me , in the future , the tables will be turned . " " " " Young lady , I come from a time when men achieve power and wealth by standing on the backs of the poor , where prejudice and intolerance are commonplace and power is an end unto itself , and you ' re telling me that isn ' t how it is anymore ? ! " " " " That ' s right . " " " " Hmm . . . maybe . . . it ' s worth giving up cigars for after all . " " " " What ' s that ? " " " " That ' s history fulfilling itself . " " " " I ' ll see you in five hundred years , Picard . " " " " And I ' ll see you . . . in a few minutes . " " Links and references . References . Alaska ; albino ; algid stage ; assayer ; aurora borealis ; brain stem ; burner ; cane ; cerebellum ; cerebral cortex ; Chinatown ; cholera ; Christianity ; cigar ; city ordinance ; Colt . 45 ; ' ; County Assayer ' s Office ; coroner ; " Croquet Scene " ; cyanotic ; Devidia II ; Devidian ; durum ; Dutch ; Earth ; earthquake ; E . B . Warehouse ; egg cream ; fairy ; Federation ; French ; gas lamp ; geological engineer ; Geological Society ; Halley ' s Comet ; Hall of Records ; ; hotel ; Hotel Brian ; hot fudge sundae ; ice cream ; James Bank ; Jesus Christ ; Klondike ; letter of intent ; London ; Market Street ; Mary ; ' ; Milan ; ; neural depletion ; neural energy ; mineral shop ; mining ; ; Oberon ; Okuda ' s Growing Seed ; ophidian ; Paris ; phase discriminator ; Pops Candy Store ; Portuguese ; prejudice ; Presidio ; Puck ; R . Moore Grocery ; rehearsal ; root beer ; San Francisco ; seltzer ; sequel ; ; Sisters of Hope Infirmary ; Spanish ; surveyor ; Swiss ; Switzerland ; tea dance ; triolic wave ; werewolf ; ; tricorder ; turbolift ; ward ; whip Unused production materials . Ashanti ; Boston ;