Sleeper ( TV story ) Sleeper was the second episode in the second series of " Torchwood " . As the title suggests , it dealt with the presence of sleeper agents having their conditioning activated , a crisis that revealed an unknown alien race was actively gathering intelligence on the Earth and might strike again one day . Synopsis . A burglary turns into a slaughter and Torchwood suspect alien involvement . When the investigation escalates into a city - wide assault , Jack realises the whole planet is in danger . Plot . Beth and Mike are a married couple who are awoken from sleep when they hear someone in their house . Mike grabs a cricket bat , while Beth calls the police . Two burglars enter their room , knock Mike out , and threaten Beth . An unseen , violent struggle occurs as a lamp by the bedside glows brighter and brighter . The Torchwood team soon arrive at the couple ' s flat , where one of the burglars is dead and the other severely injured . Tosh and Jack investigate the scene , while Gwen and Owen go to the hospital to interview the husband and wife , as well as the surviving thief . An officer at the crime scene and Gwen both suspect that the husband was responsible , citing the fact that he kept a cricket bat in the bedroom . Jack and Owen both suspect the wife though , with Owen claiming , " It ' s always the one you least suspect . " Beth claims to remember nothing , however . Owen and Gwen stay until the burglar regains consciousness . Upon being questioned by Gwen , he confirms that " the woman " did it before he flatlines . Beth is brought to the Hub ' s interrogation room . Jack attempts to get her to confess , showing her the crime scene photos and questioning whether she might be covering for her husband , but to no avail . Although a body scan reveals nothing either , a power surge also occurred at the hospital while Beth was there . Owen then tries to draw blood from her arm , only for the needle to snap : twice in a row . He then breaks a scalpel against Beth ' s arm with nary a scratch . Beth also claims to have never been sick . Having seen enough , Jack tells her to stop pretending she ' s not an alien . When Beth claims that aliens don ' t exist , he takes her to a holding cell and shows her a Weevil . While Beth continues her disbelief , the Weevil cowers at her presence . Unable to explain the oddities surrounding her , she asks Jack how she can prove she ' s not an alien . Jack decides to use a mind probe on her , despite Ianto ' s objections that the head of the last alien they used it on exploded . Gwen comforts Beth as she ' s strapped in . The mind probe begins , with Beth appearing in great pain . Gwen objects , but Owen assures her it ' s safe and Jack tells them to go deeper , as Beth is still claiming to be human . The lights flicker and Beth ' s heart rate rises and still Jack insists on continuing . Beth eventually passes out . But Jack ' s persistence pays off , as Beth immediately sits up rigidly , the skin on her right arm transforming into a ridged formation — spotted with several glowing lights . Despite attempts to talk to her , she repeats the same words in an alien language , which Jack identifies as her name , rank and serial number . Jack relates to the team what he knows about the species , which isn ' t much , as they leave no survivors . The aliens , which he calls Cell 114 , infiltrate planet s by disguising themselves as the local inhabitants and relate information back to their superiors , with the sleeper agents being completely unaware . Tosh shows the team an implant inside Beth ' s arm , where the data is stored , which is protected by a force field . The decision is made to tell Beth what she is . She is quite distraught at the revelation , questioning whether her memories and feelings for her husband are even real . Gwen assures her that her humanity does not only lie in her body , but in her mind as well . Beth asks if they will kill her and if they have killed other aliens . Gwen tells her that they have , but only when in a " kill - or - be - killed " situation . Beth wishes that she had never found out and that she could live a normal life . Jack points out that she would change on the day of the attack . Beth protests that she is not that person . Jack disagrees . Back in the Hub ' s main area , the team debates what to do with her . Toshiko suggests freezing her . Although Jack objects that she could still transmit data , Tosh believes she can single out the transmitter and disable it . As Jack and Gwen lead Beth out of her cell , the memories of her attack on the burglars begin to return . As she ' s prepared to be frozen she asks that if they cannot figure out how to make her human , that she be prevented from hurting anyone , permanently , to which Jack agrees . Tosh concentrates an electromagnetic pulse on her arm and then Owen sedates her . However , unbeknownst to the team , Beth ' s implant reactivates , sending a signal elsewhere . Throughout Cardiff , seemingly ordinary people stop what they are doing as they are activated , abandoning their jobs and families , with some even killing their loved ones who try to stop them . Back at the Hub , Beth wakes up in her cryochamber and breaks out of it , setting off alarms . Since her implant gathered information about the Hub , she is easily able to exit through the tunnels . Owen theorises that her body merely projected what they expected to see and that her vital rates did not drop to zero as they believed . Jack does not think Beth has activated , as she could have killed them all if she had . Beth has gone to the hospital to say goodbye to Mike . She tells him she will only hurt him if she stays . He protests as she hugs him that nothing she could do would be worse than her leaving him . They are both surprised at a sudden sound and look down to see that Beth ' s arm has morphed into a spike , which is now protruding from Mike ' s chest . Distraught , she calls for help . Jack and Gwen arrive and take in the scene . Beth insists it was an accident . Gwen scans Beth ' s arm to check that it ' s safe . When Beth refuses to leave Mike , Jack and Gwen are forced to drag her out of the room before hospital staff arrive . Elsewhere , Patrick Grainger , the leader of the local council , begins his day with his family . When the doorbell rings , he goes to answer the door . One of the sleeper agents , David , is at the door . After confirming Patrick ' s identity , David morphs his hand into a spike and runs Patrick through with it repeatedly , in front of Patrick ' s family . Patrick ' s wife begs for the lives of her children , but David makes no reply other than to stab her husband one more time and leave . Meanwhile , another sleeper uses a fuel tanker to destroy both a motor way and an underground fuel pipeline used by the military in emergencies . Torchwood realise that more sleepers have activated and scramble to coordinate a plan . However , the team is cut off from one another when another sleeper destroys a telecommunications station . Jack and Gwen urge Beth to try to connect with the other sleepers so they can prevent more deaths . She activates her implant and tells them that only one remains : David . While Owen , Gwen and Tosh are panicking at the lack of communications , Jack rigs up a CB radio to contact them with . He tells them David is heading for an abandoned farm and that he needs to know why . Ianto and Tosh ' s research reveals that there is a stockpile of ten nuclear warheads stored in a mineshaft at the farm . Jack theorises that this is how the cells are so effective : they use the weapons of the people they conquer against them . As the team in the Hub ponders what will happen if Jack and Gwen don ' t reach the sleeper in time , Owen suggests that they all have sex . Ianto bemoans that the end of the world has become worse . David arrives at a military compound and decimates the soldiers guarding it , as they are unable to fell him with bullets . His way cleared , the sleeper proceeds to break through the entrance ' s security codes with ease . As he breaks through the final lock , Jack runs David down with the Torchwood SUV . Nonetheless , David gets back up and stabs Jack through the chest , taunting him that they know all about Torchwood and that they will be factored into the invasion plans . Gwen uses the scanner to disable David ' s transmitter and shielding . Pulling himself off the blade , Jack shoots David and demands to know when the others are coming . David claims that they are there already . Laughing madly , he detonates his suicide implant , as the others run to get clear . Later , Gwen and Beth are in the Hub , preparing for Beth to be frozen . Beth claims that while the guilt of what she has done is horrific , what she fears more is losing it and becoming an uncaring murder er . She thanks Gwen for being so kind to her and wants her to remember her for who she was . Beth then morphs her arm into its blade form and holds it to Gwen ' s throat . As the team all surround them , guns drawn , Gwen tells them that it ' s a trick ; that Beth wants them to kill her . Beth denies this , claiming that she will kill every human . As she raises her arm as if to strike , the team all fire at her , killing her . Gwen protests that she would not have hurt her . The team assure her that they couldn ' t take that risk and that Beth knew that . Jack comforts Gwen as she looks on Beth ' s body . That night , Gwen and Jack discuss Gwen ' s upcoming wedding and whether or not they stopped the invasion . Gwen believes that even if they have not , they know more now than they did and that they can fight . Story notes . " to be added " Filming locations . " to be added "