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 utilize 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”.
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 worms – 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 shape-change 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 realizes 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 shape-changing. 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. The Doctor gives them the items from the vault as their payment, but realizes 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 traveler, 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. 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…”