Cause and Effect ( episode ) The destruction of the " Enterprise " near a distortion in the space - time continuum causes a temporal causality loop to form , trapping the ship and crew in time and forcing them to relive the events that led to their deaths . Summary . Teaser . The in dire straits , with the starboard warp nacelle having suffered extreme damage from an impact . As casualty reports flood in and the ship ' s systems start failing , Commander Riker orders all hands to escape pod s as La Forge tries desperately to shut down the warp engines . At that moment , the nacelle completely blows out , sending the " Enterprise " into a helpless spin . Data reports that the engine shutdown failed , ejection systems are off - line , and a warp core breach is imminent . As a fire engulfs the bridge , Captain Picard orders all hands to abandon ship . Alas , it is too late , as the " Enterprise " explodes killing everybody aboard . Act One . Despite its previously depicted destruction , the " Enterprise " , intact and undamaged , is traveling at impulse through space . Data , Riker , Worf , and Dr . Beverly Crusher are in the first officer ' s quarters to play a game of poker . Data shuffles the cards very fast , and because of his android nature Riker and Worf question whether Data is truly randomizing the deck . Data deals the cards and Crusher has the highest hand . The four officers play and eventually a standoff occurs between Riker and Crusher . Crusher calls Riker ' s bluff and wins the hand , somehow knowing that she would win . After winning , she is called to sickbay by Nurse Ogawa . Upon arriving at sickbay , La Forge tells her that he is feeling dizzy . Crusher finds that although he has the symptoms of an inner ear infection , there is nothing physical to suggest that he has such an infection . After examining him , she prepares a hypospray of vertazine when she has the odd feeling that she has already performed this examination . La Forge has no recollection and suggests that she was talking about another patient but Crusher is insistent that it was La Forge whom she treated . She shrugs off her " déjà vu " and administers the hypospray . Later that night , she gets ready to go to bed and shortly after she does , she starts to hear a voice and that voice soon becomes many voices , which are completely undecipherable . As Crusher puts the light on , the voices stop and she accidentally breaks her wineglass , which was next to her light switch . The following morning , the senior staff ( except for Worf ) are briefing each other on the vast undertaking of charting the Typhon Expanse in the observation lounge . As they are about to return to duty , Dr . Crusher reports the voices that she heard the previous night . The other staff are curious about her report and they are interrupted when Worf reports from the bridge unusual sensor readings in the vicinity of the " Enterprise " . The staff return to the bridge , where Worf reports that there is a localized distortion in the space - time continuum . Picard orders Ensign Ro to back the " Enterprise " away slowly but she can ' t as the maneuvering thruster s fail to respond . The distortion begins to fluctuate and power levels drop . Counselor Troi warns the captain that they must leave immediately . Data reports that something is emerging from the distortion and an unidentified starship emerges . The ship is on a collision course with the " Enterprise " , just thirty - six seconds from impact and the helm still fails to respond . There is no response when the " Enterprise " hail s the other ship . Picard asks for suggestions . Riker ( standing closely to the left of Data ) suggests decompressing the main shuttlebay allowing the explosive reaction to push them clear while Data alternatively suggests using the tractor beam to alter the ship ' s trajectory ; Picard opts for the latter . The " Enterprise " emits a tractor beam but it is insufficient as the ship collides with the " Enterprise " s starboard warp nacelle , causing it to explode . The events portrayed in earlier replay themselves and again the " Enterprise " is destroyed by a warp core breach . Act Two . Once again intact , the " Enterprise " is traveling at impulse through a familiar region of space . Data , Riker , Worf , and Dr . Crusher are in Riker ' s quarters playing a game of poker . Data shuffles the cards very fast and because of his android nature and Riker and Worf question whether Data is truly randomizing the deck . Data deals the cards and Crusher once again has the highest hand . Each player bets and as Data is about to deal another round , Riker now feels " déjà vu " and eyes Crusher , having a strong feeling about the outcome of the game and he folds , telling her that she will call his bluff . Crusher eyes Riker back in surprise and asks him how he knew . Riker replies that he " just had a feeling " , as did Dr . Crusher . Crusher is called to sickbay and , upon arriving at sickbay , La Forge tells her that he is feeling dizzy . Crusher finds that although he has the symptoms of an inner ear infection , there is no physical evidence of one . After examining him , she prepares a hypospray of vertazine , but she has the odd feeling that she has already performed this examination . When she asks La Forge if she did this examination before , La Forge says he too has the feeling that she has , but they cannot remember when . Crusher checks the medical logs on La Forge and finds that although La Forge recently had complaints about pain with his VISOR , he had none regarding dizziness . La Forge suggests that it was " déjà vu " but it was unlikely , since both of them had the feeling . Later that night Crusher is in her quarters getting ready for bed and as she does , she hears whispers becoming louder and more frequent . She gets up and calls Captain Picard and at the same time , breaks her glass which was next to the light switch . In the ready room , Picard and Crusher share their recent feelings of " déjà vu " ; while reading , the captain started to feel as though he had read certain paragraphs before but dismissed it ( assuming he must have read that same book years ago ) . Picard orders a ship - wide diagnostic with a report to be made in the morning . At 0700 hours , the senior staff ( except for Worf ) discusses the results and finds no anomalous readings in the diagnostic , although Crusher discovers that ten other people aboard the " Enterprise " heard voices at the same time of the night as she did . Worf interrupts from the bridge and reports that there is a distortion in the spacetime continuum in the vicinity of the " Enterprise " . The staff returns to the bridge . Picard orders Ro to have the " Enterprise " back off slowly but maneuvering thruster s fail to respond . The distortion begins to fluctuate as power levels on the ship drop . Counselor Troi warns Picard that they have to leave now . Data says that something is emerging from the distortion and a starship appears . The ship is on a collision course with the " Enterprise " , just thirty - six seconds from impact and the helm still fails to respond . There is no response when the " Enterprise " hails the other ship . Picard asks for suggestions . Riker suggests decompressing the main shuttlebay allowing the explosive reaction to push them clear and Data suggests using the tractor beam to alter the ship ' s trajectory ; Picard opts for the latter . The " Enterprise " emits a tractor beam but again it is too late – the ship collides with the " Enterprise " s starboard warp nacelle , causing it to explode . The previous events replay themselves once more and again the " Enterprise " is destroyed by a warp core breach . Act Three . The " Enterprise " is traveling at impulse through space . Data , Riker , Worf , and Crusher are in Riker ' s quarters to play a game of poker . Data shuffles the cards very fast because of his android nature and Riker and Worf question whether Data is truly randomizing the deck . Data deals the first set of cards , face down , and Worf is agitated , having the feeling of having done this before , quoting " nIb ' poH " , the Klingon equivalent of " déjà vu " . Riker says that they have done this before , last Tuesday for the previous poker night but Worf means " déjà vu " and Crusher has the same feeling . Data now deals the cards face up and Crusher predicts that she will get a queen ; she does . She then predicts that Data will get a four ; he does . She then tells Data to deal the cards and she , Riker and Worf are overcome with feelings of " déjà vu " , flawlessly recalling the order of the cards that would be dealt . They all wonder how they knew . Crusher interrupts the puzzlement and calls sickbay asking if La Forge is present but is told he isn ' t . La Forge soon arrives in sickbay and the CMO leaves . Picard arrives in sickbay seeing Crusher and La Forge – La Forge ' s VISOR is being examined with a diagnostic tool while a test is being done on his visual receptors . Crusher asks Picard if he has been experiencing " déjà vu " as of late ; he has , as have many other people aboard the ship . Crusher has foregone running a standard test on La Forge in favor of running an optical diagnostic where the results came back positive for a phase shift in his visual receptors , which caused his dizziness as the phase shift was projecting images that didn ' t exist . Small distortions were found in the surrounding dekyon field and La Forge ' s VISOR was converting these distortions into the images that he was seeing , causing his dizziness . Later that night , Crusher is getting ready for bed ( dressed in her uniform ) and puts her glass on a table rather than next to the light switch . As she goes to bed , she starts to hear voices again . She immediately gets up , prepared with a tricorder and records the voices . She calls La Forge , reporting the voices and La Forge reports that something strange happened as well . As she goes out , her coat hits her glass which falls and breaks . Crusher joins La Forge and Data in main engineering . La Forge reports that there was a distortion in the dekyon field . They analyze Crusher ' s six - second recording , and Data discovers that there are over one thousand voices , all coming from the crew of the " Enterprise " . Act Four . Crusher calls all of the senior staff ( Worf is now present ) to the observation lounge early in the morning with a suggestion as to what was causing all of the unusual events that happened recently on the " Enterprise " . La Forge reports that the " Enterprise " has most likely been caught in a temporal causality loop , where they have been repeating events over and over again but they have no knowledge of how many times they have repeated events or how long they have been stuck in the loop . Crusher feels that if La Forge is correct , then the voices that she heard may be " echoes " from previous loops . Picard inquires how the " Enterprise " may have been caught in the loop . Data hypothesizes , from the recording , that the " Enterprise " had encountered a disaster so serious that the captain would order all hands to abandon ship and replays three segments of the recording – Worf ' s report of the distortion , Data ' s report on the collision course and Picard ' s call for all hands to abandon ship . The staff are clearly disturbed by what they just heard . La Forge suggests that if the distortion was a temporal distortion then the destruction of the " Enterprise " may have caused a rupture in the space - time continuum , catching them in the loop . Worf suggests that they reverse course to avoid the disaster , but Riker points out that reversing course could be what causes the disaster . Picard decides that they cannot start second - guessing themselves ; he orders them to remain on course . La Forge warns that if the disaster is not averted they will forget everything that they learned in this loop . La Forge and Data suggest modulating a dekyon emission which , if done correctly , would set up a resonance in Data ' s positron ic subprocessors , leaving a message . However the message would be very short ( a few characters or a word at most ) and Data would not know what the message is immediately ; it would be more like a post - hypnotic suggestion . La Forge , Data , and Crusher are in main engineering where La Forge is making some modifications to the circuitry in Data ' s head , and he attaches an emitter to Data ' s right arm . Neither La Forge nor Crusher recall having done this before so they feel encouraged . La Forge tests the modifications and finds an active dekyon field . Red alert is called and the three officers return to the bridge . The distortion is present again and the same events happen like before but this time Data is able to input a message on the emitter on his arm just before the " Enterprise " is destroyed . Act Five . The " Enterprise " is traveling at impulse through space . Data , Riker , Worf , and Crusher are in Riker ' s quarters playing a game of poker . Data shuffles the cards in his typically fast android fashion and Riker and Worf question whether Data is truly randomizing the deck . Data deals the first set of cards face down – however Worf is agitated – feeling as if he has done this before . Riker says that they did last Tuesday , but Worf means " déjà vu " – and Crusher reports having the same feeling . As Data is about to deal the next set of cards face up , Crusher attempts to predict the order of the cards ( the way she did in the previous loop ) but this time they are all threes . Crusher is surprised , as she was " certain " she knew which cards would be dealt . Worf shared the same surprise and the same conviction . Data deals three more rounds and this time all four officers are dealt three of a kind . They are all surprised with the improbability of what just happened . Crusher is then called to sickbay by Nurse Ogawa . When she arrives at sickbay , La Forge complains of dizziness and she performs an exam and the results came back negative . She then runs an optical scan and calls Captain Picard down ( while he experiences his " déjà vu " while reading ) , reporting to him her findings as she did previously . La Forge then leaves and returns to engineering . Data and La Forge are in main engineering and Data runs a diagnostic on the warp subsystems . When he finishes the diagnostic , the results come up entirely as threes . Data says that he has encountered the number three " an inordinate number of times " in the past two hours . La Forge receives an alarm of a distortion in the dekyon field on Deck 9 . Crusher ( from her quarters ) calls La Forge and reports the voices while La Forge reports the dekyon distortion . Crusher leaves her quarters and heads for engineering . As she leaves , Data and La Forge hear a glass shatter , and after asking if everything is okay , Crusher reports that she is fine and continues on her way . Some time later , the senior staff is in the observation lounge , half - way through discussing the theory of being caught in the causality loop . La Forge and Data report the many sightings of the number three occurring all over the " Enterprise " , knowing that it is more than a coincidence . Nothing was wrong with the ship , but a diagnostic revealed that there was a dekyon field modulation in Data ' s positronic subprocessors . They didn ' t know what caused it , but La Forge said that if he wanted to send a message , he ' d do it in a similar fashion . The staff discuss the significance of the number three . Riker asks that La Forge perform a level 3 diagnostic when they are interrupted by Ensign Ro on the bridge . The staff return to the bridge and once again the distortion is present . As before , Picard orders the " Enterprise " to back off slowly but maneuvering thrusters fail to respond . The distortion begins to fluctuate and events begin to repeat themselves yet again as the unidentified starship emerges on a collision course . Also as before , Picard asks for suggestions and Riker suggests decompressing the main shuttlebay while Data suggests using the tractor beam . Picard opts for the latter but just before Worf engages the tractor beam , Data ' s gaze is caught by the sight of Riker ' s rank pips and the android is struck by a moment of realization . He deduces that using the tractor beam will not succeed and instead follows Riker ' s suggestion of decompressing the main shuttlebay . The bay door opens with gas violently rushing out , successfully pushing the " Enterprise " out of the path of the other ship and saving it . Power is restored and Picard asks Data what happened . Data speculates that " three " referred to the number of rank insignia on the neck of Riker ' s uniform , indicating that his suggestion would be the successful course of action . Red alert is canceled and Picard orders Worf to access a Federation time - base beacon to ascertain how long they have been in the causality loop . The beacon confirms that the " Enterprise " s chronometers are off by 17 . 4 days and Data resets them accordingly . The " Enterprise " is then hailed by the other ship , which the " Enterprise " identifies as the , a starship , a class which had been out of service for more than eighty years . The " Enterprise " opens a channel and the " Bozeman " s Captain Morgan Bateson offers assistance while Picard was going to offer assistance as well . Bateson is unfamiliar with the configuration of the " Enterprise " and he explains that they found a temporal distortion inside the expanse , then the " Enterprise " suddenly appeared with the " Bozeman " stuck on a collision course with it . Picard tells Bateson that the " Enterprise " was caught in a temporal causality loop and suspects that something similar happened to the " Bozeman " . Bateson dismisses Picard ' s suggestion , claiming that the " Bozeman " left starbase only three weeks previously , but when Captain Picard asks Bateson what the year is , Bateson replies saying that it is 2278 . Realizing the " Bozeman " has been thrust a full ninety years into the future , Picard suggests that Bateson beam aboard the " Enterprise " as there is much to discuss . Memorable quotes . " " All hands abandon ship ! Repeat : all hands abandon . . . " " " " Still no help for the Klingon . " " " " My Aunt Adele cured a lot of sleepless nights with this steamed milk . " " " " Sometimes I wonder if he ' s stacking the deck . " " " " I assure you , Commander , the cards have been sufficiently randomised . " " " " I hope so . " " " " I am experiencing nIb ' poH , the feeling I have done this before . " " " " Yeah , last Tuesday night . " " " " That is not what I mean . " " " " I ' ve been having the same feeling . " " " " How ' d you know I was bluffing ? " " " " I just had a feeling . " " " " I guess it ' s better to be lucky than good . " " " " It ' s the way your left eyebrow raises when you ' re bluffing . " " ( Riker looks shocked ) " " Just kidding , commander . " " " " I ' d like to run an optical diagnostic . " " " " For an ear infection ? " " " " This is highly improbable . " " " " This is going to sound pretty wild . " " " " Must be " déjà vu " . " " " " Both of us ? About the same thing ? " " " " Back us off , ensign . Nice and slow . " " " " Somehow we ' ve entered what seems to be a temporal causality loop . We think we ' re stuck in a specific fragment in time and that we ' ve been repeating that same fragment over and over . " " " " Is this what ' s causing our deja vu ? " " " " Yes , but it ' s more than that . In deja vu , you only think you ' re repeating events . We actually are . " " " " Our theory is this : every time the loop begins again , everything resets itself and starts all over . We don ' t remember anything that happened before , so each time we go through the loop , we think it ' s the first . " " " " To date , we have encountered 2 , 085 conspicuous examples of the number three . " " " " The tractor beam will not be successful . I am decompressing the main shuttlebay . " " " " Captain . . . do you know what year it is ? " " " " Of course I do – it ' s 2278 . " " " " Perhaps you should beam aboard our ship . There ' s something we need to discuss . " " Links and references . References . 2336 ; 2353 ; 2357 ; 47 ; acoustic energy ; Adele ; African Confederation ; " Berman " ; ; casualty report ; catwalk ; common cold ; damage report ; dealer ; deja vu ; dekyon ; dizziness ; drive plasma ; escape pod ; evasive maneuvers ; explosive decompression ; eyebrow ; Federation ; ; graviton polarimeter ; headache ; inertial damper ; insomnia ; Klingon ; Klingonese ; main shuttlebay ; " " ; milk toddy ; Mogadishu ; nutmeg ; paragraph ; patient ; " Piller " ; plasma ; poker ; positronic net ; rank insignia ; red alert ; Somalia ; ; Starfleet Academy ; stellar dynamics ; subspace scan ; temporal causality loop ; time - base beacon ; tricorder ; Typhon Expanse ; vertazine ; VISOR ; warp core breach ; warp core ejection system ; warp nacelle