Power Play ( episode ) Alien entities take over the minds of Data , Troi , and Miles O ' Brien . Summary . Teaser . As the attempts to identify the source of the distress call , they are confronted with extreme interference due to electromagnetic whirlwinds on the moon , which renders the sensor s incapable of picking up life sign s . However , Commander Data is able to identify the distress call to be consistent with that of starship s , which , however , have not been in service for 172 years . Captain Picard asks Data to check if any starships have been reported missing in this area . Data determines that the under the command of Captain Bryce Shumar disappeared in the vicinity , over two hundred years ago . He also determines , that the signal from the moon is identical to the subspace signature from the " Essex " . The captain thinks that they have solved the mystery of the " Essex " , seeing no need to beam down to check a ghost ship , and orders Lt . Worf to notify Starfleet . However , in that moment , Counselor Deanna Troi tells the captain that they have not necessarily solved the mystery of the missing ship , since she senses life on the moon ' s surface . Act One . William T . Riker , Data , and Troi are on board the shuttle " Campbell " on their way down to the moon surface . However , the shuttle is continually being shaken by the winds , until some systems fail and the crew are forced to emergency land on the moon ' s surface . On the " Enterprise " , the crew are worried about the people on the shuttle , however , Ro Laren is able to determine the coordinates where the shuttle crashed . The crew in the shuttle manage to release the exit door of the shuttle . However , they are unable to communicate with the " Enterprise " , and all equipment in the shuttle has been rendered inoperable . Riker ' s arm has been broken in the crash . Troi notices an odd - looking storm front close to their own position . Data does not pick up any life signs in the front with his tricorder , but Troi is absolutely certain that there is life , and it is approaching along with the storm . On the " Enterprise " , Geordi La Forge and Chief O ' Brien are attempting to find a way to beam the away team from the surface . O ' Brien suggests that he beam down by boosting the confinement beam and he will bring with him a set of pattern enhancer s , which would allow safe transport for the away team . La Forge reminds the chief that the chances of him making it down to the surface are 50 / 50 at best , but O ' Brien insists that he be allowed to try . As Worf informs Captain Picard that a storm front is moving towards their crew on the moon and Picard allows O ' Brien to take the risk . O ' Brien manages to beam down to the away team and starts distributing the pattern enhancers . However , as he tries to activate the third enhancer , it is struck by a violent lightning , knocking the four crewmembers over on the ground . As they lie unconscious , the storm passes over them and glowing orbs enter the bodies of O ' Brien , Data , and Troi . A fourth one passes over Riker , but will not enter and flies away instead . He gets up and activates the third pattern enhancer , and the crew are beamed up to the ship , with Data , Troi , and O ' Brien still unconscious . Act Two . Now in sickbay , Troi ' s eyes move rapidly and she screams as she opens her eyes . Doctor Crusher comes to calm her down . The rest of the away team are also in sickbay and have all recovered consciousness . Captain Picard enters sickbay to check on his crew and finds them all in a fairly good condition . Troi , Data , O ' Brien , Riker , and Picard then enter a turbolift to the bridge . In the turbolift , Data explains how they can continue with the investigation . However , there is a short audible buzz in his voice , which he dismisses as a fluctuation in his speech processors . He claims that he will have it corrected shortly . On the bridge , Troi asks Picard to have a word with him in private and they proceed to his ready room . Riker orders Ensign Ro to take a synchronous orbit around the shuttle ' s crash site , but Data claims that due to the EM - patterns it would be best if they begin the search around the southern polar region . Riker is skeptical and maintains his request to begin the search at the crash site . There is a visible reluctance on Data ' s face as he hears that . In the captain ' s ready room , Troi claims that the entities she sensed on the moon surface were calling her to the southern polar region . She recommends that they should look for the " Essex " there . On the bridge , Ro notices that she has been locked out from the helm , but Riker has no explanation for it . He asks Data what may have happened , but Data does not answer . As Riker walks up to Data ' s console , Data hits Riker and knocks him on the floor . As Worf tries to fire a phaser on Data , he is pulled away and knocked over the tactical station by O ' Brien . Ro tries to stun O ' Brien with a phaser of her own , but he takes cover and shoots her . Riker manages to transfer all bridge control to engineering , which completely locks out Data from his console . In his ready room , Picard gets knocked on his back by Troi . Data , O ' Brien , and Troi enter the turbolift and proceed to engineering . Riker restores bridge control and Worf walks up to tactical station . There he overrides the control for the turbolift and stops it at deck ten . However , O ' Brien has sufficient technical skills to override the bridge command and can get the turbolift to move again . Picard orders Worf to engage emergency bulkhead s in the turboshaft . The turbolift is stopped at deck 13 and Picard orders Worf to take a security team there . However , when the security team opens the door of the turbolift , it is empty except for Troi ' s , Data ' s , and O ' Brien ' s combadge s . On deck ten , the three walk through a corridor , as they get trapped by force fields . Data smashes a computer console on the wall and touches the exposed circuitry , thereby connecting with the computer and overriding the force field . Picard is informed of their break - free and location , and realizes the three are on their way to Ten Forward and sends security there . In Ten Forward , Keiko O ' Brien , Miles ' wife , tries to calm her daughter , Molly , who is hungry and crying . In that moment , Troi , Data , and O ' Brien enter Ten Forward and force everyone on the floor . A security team arrives , which results in a phaser shoot - out . However , none of the phasers seems to have any effect on any of the three and they successfully seize control over Ten Forward . When Picard attempts to contact Worf from the bridge to see what transpired when the security team reached Ten Forward Troi refuses to let him answer . Instead , proving her control over the situation , she points a phaser at Worf and responds firmly , " Yes bridge , he can hear you . " Act Three . On the bridge , the crew try everything they can to get the situation under control , but without any success . Data isolates Ten Forward with force fields and O ' Brien collects all communicators from any of the crew in Ten Forward . Meanwhile , Picard asks Dr . Crusher to see if she can find any clue as to what happened to Troi , Data , and O ' Brien . He then contacts Ten Forward and asks the captors to discuss the situation . After some delay , they respond and tell Picard to move the ship to the southern polar region . Picard orders the ensign to move the ship there , but as slowly as possible . Dr . Crusher then comes up with a possible explanation – she has determined that other life forms may have taken control over their people – Riker was not affected because his broken arm inflicted pain , which has prevented him from being taken over by the alien entity . Picard then suggest that inflicting pain on Troi , Data , and O ' Brien may free them from their possessors . Ro and La Forge come up with the possibility to fire a plasma shock on their people , which would inflict pain on Troi and O ' Brien and incapacitate Data . They suggest that they could place a micro - optic drill in the ceiling of Ten Forward from above , deactivate the force field for a short moment and then fire the plasma shock through the drill . Picard then orders Dr . Crusher to work on a way to contain the alien entities once they have been forced out . Picard then contacts Ten Forward about the injuries of the people there . Troi tells Worf to inform the bridge about the injuries . Picard then asks Troi to release the injured , in exchange for him as another hostage , and Troi agrees . Riker objects to Picard placing himself in this position , but Picard points out that the whole ship is essentially being held hostage anyway and while he ' s there he can find out who or what they ' re dealing with . He leaves with orders that if La Forge and Ro can go ahead with the plasma shock then to , but if they can ' t or if it doesn ' t work then for Riker to watch for any opportunity Picard might give him . A medical team and Picard then enter Ten Forward . Troi tells Picard that she is Captain Shumar of the " Essex " . Act Four . Stunned , Picard is in disbelief , and Troi tells him that Data is Shumar ' s first officer , Commander Steven Mullen and that O ' Brien is the security chief Lt . Morgan Kelly . She also says that she has no wish to harm Counselor Troi , who is still alive , or anybody else on the " Enterprise " . She tells Picard that they have commandeered the ship because they have been trapped on the moon for over two centuries and simply want to find rest . For that , they need the help of the " Enterprise " . La Forge and Ro have reached a service crawlway just above Ten Forward . On the bridge , Dr . Crusher has determined how she could trap the alien entities – by duplicating the magnetic flux density in the storms on the moon . However , La Forge tells the bridge that it would still take up to an hour for them to calibrate the device to fire the plasma shock . In Ten Forward , Picard and Worf have a chance to discuss the situation . Worf confides that Klingon history contains many legends of the living being possessed by the spirits of the dead , and Picard admits that Human history has many similar legends . Worf asks if Picard believes that " Shumar " and the others are who they say they are , and Picard , dropping his voice even lower , says absolutely not : if they were Starfleet officers , they would be behaving much less violently . Worf posits that , after years living disembodied on the moon , the crew of the " Essex " has gone insane . The entity inhabiting Data cuts them off and orders them to sit down apart from each other . The " Enterprise " is nearing the southern polar region of the moon and Picard asks Troi for further instructions . She demands that they beam up the skeletal remains of the " Essex " crew and bring them to Earth for a proper burial . Picard demands that all the hostages are released first , but Data threatens to kill some of the hostages if the captain does not cooperate . Meanwhile , La Forge and Ro attempt to fire the plasma charge on the three captors but they miss Data . The alien beings emerge from the bodies of Troi and O ' Brien as they slump to the floor . Dr . Crusher establishes the field that traps the alien entities . An enraged Data , still possessed , grabs Picard ' s neck and lifts him from the floor . He threatens to kill everyone in Ten Forward starting with the captain if he does not order the bridge to stop . Picard , under duress ; gives in . The bridge deactivates the field and the glowing orbs again seize control of Troi and O ' Brien . Act Five . The ship has arrived at the destination , but the electromagnetic storm activity renders the sensors useless again . The same distortion also makes the use of the transporters impossible and Picard reminds the captors that O ' Brien is the only person on board who can get the transporters to work . O ' Brien confirms this , but says he needs a transporter pad to conduct the procedure ; since there is none in Ten Forward , Picard proposes that he give them safe passage to the transporter in Cargo Bay Four . Picard signals the bridge , telling Riker they have the " opportunity " to end the violence – putting a barely noticeable emphasis on the word that reminds Riker of their earlier conversation . After some debate , the captors agree , but they each take a hostage . Troi takes Picard , Data takes Worf , and O ' Brien takes Keiko , though he agrees to her plea to leave Molly behind , and Keiko gives her to the care of another woman . They deactivate the force fields and leave Ten Forward . After arriving in Cargo Bay Four , Picard asks " Shumar " when he will really tell him who he is , but gets no response . On the bridge , Riker explains to Ro that there is only one reason why Picard chose that particular cargo bay : the bridge crew can blow the hatch and decompress the cargo bay if it becomes necessary . In the cargo bay , O ' Brien is able to modify the transporter and beams up hundreds more of the alien beings . Then , Troi tells Picard that he was right : they and the other entities are all condemned prisoners from a system called Ux - Mal , who were brought to the moon over five hundred years ago , separated from their physical bodies , and left to drift in the storms ; the moon is , essentially , a penal colony . They tried to escape on the " Essex " , but the ship was incapable of eluding the moon ' s electromagnetic storms . Now , they intend to use the " Enterprise " and the bodies of its crew to escape . On the bridge , Ro reads with alarm that hundreds of the " prisoners " are now in the cargo bay . Riker gives Picard his advantage , ordering Dr . Crusher to activate the containment field she developed . When she does , the entities are now trapped in the cargo bay . Enraged , Troi threatens to kill Picard , but he calmly tells her that her threats have no value now , reminding her that all her fellow prisoners will die if the cargo bay hatch is blown . Data says Picard and the other Humans will likewise be killed , but Keiko and Worf step forward and say they are more than willing to give up their lives to save their friends and loved ones . Picard reminds them that Troi , Data , and O ' Brien are Starfleet officers who would also give their lives in this situation . He proposes to them that if they free their host bodies , Picard will return all of the entities , unhurt , to the moon ' s surface . After some thought , the criminal inhabiting Troi gives in and warns Picard not to pass their way again . The entities leave the bodies of O ' Brien , Troi , and Data and join the others on the transporter pad . Using Troi ' s communicator , Picard informs the bridge that the siege was successfully ended and orders Worf to beam all the entities back to the moon . Troi describes her experience of being possessed , explaining that while she could see and hear everything she was doing but wasn ' t in control , and notes that the being that inhabited her was intelligent but ruthless . Data apologizes to Worf for his behavior and thanks him for his restraint , and Worf notes that Data has " no idea " how hard it was to control himself . In sickbay , Doctor Crusher finishes checking out O ' Brien and he reunites with Keiko and Molly , before apologizing for his behavior . Memorable quotes . " " Someone ' s down there . . . alive . " " " " A concussive charge would blow out the security fields . We could go in with phasers on wide beam , stun everybody . Sort it out later . " " " " I never want to see this part of the " Enterprise " again . " " " " I hear you . This is what starship designers call ' easy access ' . " " " " Lunch time , Miles ! Let ' s do it ! " " " " Everyone , get down on the floor ! ! " " " " Mr . Worf , acknowledge ! Can you hear me , Mr . Worf ? ! " " " " Yes , bridge . He can " hear " you . " " " " What are you looking at ? You , Klingon . Attack me ! " " " " Silence that child ! " " " " I have no fear of death . " " " " And I have no fear of killing you ! " " " " You have thirty seconds to change your course , or else additional members of your crew will require medical attention . " " " " Tell them to stop or I will kill everyone in this room , starting with you ! " " " ( choking ) " Picard to bridge ! Abort immediately ! " " " " Are you ready to sacrifice the lives of these others ? They ' ll all die when the cargo bay hatch is blown ! " " " " You will die too , Picard ! " " " " I would die to save the life of my child . " " " " To die defending one ' s ship is the hope of every Klingon . " " " " If you each know the officers you inhabit , then you know they ' re equally ready to give their lives for this ship . " " " " I advise you , Picard , not to pass our way again . " " " " Lieutenant , I must apologize for my inadvertent misconduct toward you . " " " " No apology necessary . " " " " Your restraint was most remarkable . " " " " You have " no " idea . " " Links and references . References . air vent ; anesthizine ; anionic energy ; anti - grav lift ; authorization code ; biofilter ; " Campbell " ; cargo bay 4 ; cargo transporter ; communicator ; concussive charge ; conduit ; confinement beam ; ; diagnostic mode ; distress call ; Earth ; electromagnetic storm ; emergency bulkhead ; ; Federation ; force field ; ghost ship ; hostage ; impulse generator ; ionic cyclone ; ionogenic particle s ; " jat ' yIn " ; Jefferies tube ; Klingon ; Klingon history ; , ; laser scanner ; Mab - Bu VI ; magnetic flux ; McKinley Park ; M - class ; micro - optic drill ; moon ; ; ; neural net ; neural pattern ; neutrino ; neutrino field ; number one ; ; pain receptor ; pattern enhancer ; penal colony ; plasma inverter ; plasma shock ; polarity ; primary speech processor ; seatbelt ; Sector 25712 ; security alert ; security lockout ; skeletal system ; ; Starbase 12 ; Starfleet ; Starfleet Academy ; subspace transponder ; synaptic activity ; synchronous orbit ; thruster ; transporter ; transporter array ; transporter pad ; tree ; tricorder ; turbolift ; turboshaft ; Type 15 shuttlepod ; Ux - Mal ; Ux - Mal entity ; wind shear