Time Heist ( TV story ) Time Heist was the fifth episode of the eighth series of " Doctor Who " produced by BBC Wales . Set around a time travel - based bank robbery , Steven Moffat had thought of the concept some years earlier before handing it over to Steve Thompson when he found a way to utilise it . Writing his third story for " Doctor Who " , Thompson borrowed concepts from the " classic heist movie " , adapting them for science fiction . The Teller came from this notion as " the ultimate CCTV system " alongside Psi and Saibra as the motley crew , endowed with specialist skills . Thompson also made a different approach to his " monster " . In " The Curse of the Black Spot " , he found that a CGI monster used up the entire special effects budget . For " Time Heist " , prosthetics were used , leaving room for CGI to create an alien world . Written before the Twelfth Doctor was cast , Thompson expressed delight at being able to write for this new Doctor , scripting him , per Capaldi ' s description , as " less user - friendly " . ( DWM 478 ) Synopsis . The Doctor and Clara receive a mysterious phonecall , and find themselves in a maximum security bank , memories wiped clean and two more recruited strangers to accompany them . Their mission : to rob from a bank that lives up to the reputation of impregnability , but will they be able to find out what they ' ve been recruited to steal and why before they get captured ? Plot . The Twelfth Doctor tries to convince Clara to come with him for a day sightseeing via the TARDIS , but she is about to go on a date with Danny Pink . As she is about to leave , the TARDIS phone rings , despite both knowing that very few beings in the universe have access to that . The Doctor goes to answer the phone , and suddenly the two find themselves in a strange chamber suffering from memory loss along with two others , an augmented human , Psi , and a mutant human , Saibra . Both have also suffered memory loss , with the likely culprit — memory worm s — wiggling around on the table . A briefcase on the table opens to reveal plans by " The Architect " , who instructs them to rob the Bank of Karabraxos , the most impregnable bank vault in the universe with numerous levels of security . There ' s no chance of backing out either — they ' re already " in " the bank and guards are trying to break into the room — and Psi downloads the instructions into his head as the group flees . The pursuit is slowed when the guards handle the memory worms , unaware of their abilities . They work their way back into the main floor of the bank , with Saibra — whose mutation allows her to shapechange into any living thing she touches — using the identity of a bank customer whose DNA had been included in the case to get them in . They witness another customer , accused by the bank head of security , Ms . Delphox , of intending to steal from the bank , having his brain scanned and then turned to " soup " by the Teller , an alien with powerful psychic abilities that is said to be the last of its kind . The Doctor , Clara , Psi , and Saibra continue to follow the Architect ' s plan , finding more cases with useful items left by their mysterious boss as they get closer to the main vaults . At one point , they collect six devices whose purpose the Doctor claims he does not know , but Saibra points out he ' s lying - having had so many faces , she knows how to read people better than most . The Doctor is forced to admit the devices are an " exit strategy " . Part of the plan requires them to pass through the cage where the Teller is kept in near - hibernation , but it picks up on Clara ' s brainwaves . The Doctor helps Clara break out of the Teller ' s scan and has the group flee the room , but Saibra is caught in the scan . The Doctor gives her one of the devices , telling her it is an atomic shredder , a more humane way to die than the Teller ' s brain scan . She activates the device and disappears . As the three continue to the vault , they find that Ms . Delphox has released the Teller to chase them down . Psi stays behind to help cover their tracks and open the vault ; he , too , opts to use one of the disintegrators when he is caught by the Teller . The Doctor and Clara eventually reach the main vaults , and , as a solar storm begins to strike the surface of the planet , the Doctor realises this wasn ' t just a bank heist , but a " time " heist — the Architect is from the future , and planned to bring them to the vault at this moment when the storm ' s activity would cause the main vault to automatically open . They locate two safe boxes indicated by a note from the Architect , one containing a neophyte circuit that can restore Psi ' s deleted memories , and the other a gene suppressant to stabilize Saibra ' s uncontrollable shapechanging . However , as they look for the final safe box location ( in the Private Vault ) , they are caught by the Teller and taken to Ms . Delphox ' s office . Ms . Delphox leaves to put the Teller back into hibernation to protect him from the worsening solar storm , ordering her guards to kill the intruders . The Doctor and Clara are surprised when the guards turn out to be Saibra and Psi - the disintegrators were really teleporters linked to a ship in orbit . The Doctor gives them the items from the vault as their payment , but realises they still need to find the Private Vault . Psi leads them into the depths of the bank as the storm intensifies on the surface . At the Private Vault , they find that it is the quarters of Ms . Karabraxos , surrounded by treasures from around the galaxy . The Doctor realises Ms Delphox is just a clone of Karabraxos , and she has no problem sending her clone to be incinerated for failure . Witnessing such self - loathing , inspiration strikes the Doctor , and he writes the number to the TARDIS telephone , and that he is a time traveller , on a piece of paper and gives it to Karabraxos , who is hastily packing her treasures before the storm wipes out the bank . She departs from the vault , but the Doctor reminds her to give him a call one day if she has any regrets . Shortly after she leaves , the Teller arrives , and the Doctor convinces him to scan his mind to find the memories that were blocked . In a flashback , an elderly and dying Ms . Karabraxos — now no longer the richest person in the universe — calls the Doctor on the TARDIS in Clara ' s flat , and tells him of her regret . The Doctor is then shown preparing all the elements of the time heist , revealing that he himself was the Architect . Because much of the bank ' s security was based on sensing a criminal ' s guilt , wiping the recent memories of the heist participants would reduce their chances of being caught . The ultimate goal of the plan was to bring the Teller , who was telepathically linked to Karabraxos , to the Private Vault after she left , so as to allow him to unlock a combination safe . Inside , they find another alien of the same species as the Teller , chained within the safe . The Doctor points out that they have " six " teleport devices , allowing them all to escape the bank before it is wiped out . The Doctor takes the creatures to an isolated planet to live out their lives free of telepathic " noise " , and then returns Saibra and Psi to their respective times and places after having lunch . Finally , the Doctor returns them to Clara ' s flat moments after they have left to allow Clara to continue on her date . Right after she departs , he declares with a smug grin , " Ha ! Robbing a bank ! Robbing a whole bank . Beat " that " for a date . . . " Story notes . Ratings . 6 . 99 million ( DWM 479 ) External links . " to be added "