The Return of Doctor Mysterio (Christmas 2017) In New York City on Christmas Eve of 1992, an 8-year-old boy named Grant wakes to find the Doctor dangling outside the window of his family's apartment and helps him come into his bedroom. Taking the boy to the rooftop, the Doctor reveals he accidentally set off a trap for a device he was building, and he enlists Grant to help complete it. However Grant mistakenly swallows a wish-granting gemstone needed for the device, believing it to be medicine, effectively being granted his wish to be a superhero. Abandoning the device, the Doctor makes Grant promise to not use his new superpowers before he leaves. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

The Pilot The Doctor and Nardole are living under the guises of a university professor and his assistant. Bill Potts, who works at the university's canteen, is called to the Doctor's office, where he notes she attends all his lectures, and Bill eventually becomes the Doctor's student.

Months pass, and Bill develops a mutual attraction to a student named Heather, who has a defect that makes it look like there is a star in her eye. Heather asks her to inspect a mysterious puddle, asking her if she can see what's wrong with her reflection, but Bill does not notice anything except that her face seems wrong somehow. Bill turns around and Heather has left. Within the puddle, a voice proclaims that a search for a pilot has begun. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

Smile Despite Nardole's caution, the Doctor allows Bill to select her first destination for a trip in the TARDIS. They land in the far future on an off-world Earth colony. The colony is empty except for millions of nanobots called the Vardy that maintain it, along with robotic avatars that interact with the pair via emoji. The robots give the Doctor and Bill badges which report their emotions also through emoji-seemingly the only way to communicate with the Vardy.

The Doctor suspects they have arrived before the full colony ship is due, but remains curious as to the absence of any type of pre-colony crew preparing for their arrival. They discover the bones of these humans being used for fertiliser. The Doctor realises that if the Vardy sense they are not happy, the nanobots will consume them to their skeletons, and warns Bill to keep smiling as they escape. The Doctor locates the ship that brought the pre-colony crew to the planet, planning on overloading its reactor to destroy the Vardy before the arrival of the unsuspecting colonists. However, Bill discovers a young boy who leads her to a large number of hibernation chambers including some humans just awaking; the Doctor realises that this is the colony ship. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

Thin Ice The Doctor and Bill find they have arrived in London in 1814, in the midst of a frost fair on the frozen Thames. After dressing in period garments, they take to explore it, unaware the TARDIS sensors have identified a large life form, a kilometre long, under the ice.

The Doctor's sonic screwdriver is stolen by Spider, one of several orphan pickpockets led by Kitty. The Doctor and Bill chase down Spider and Kitty away from the fair. There, glowing lights under the ice encircle Spider's feet and before the Doctor can save him, Spider is pulled through the ice. Bill is troubled by the Doctor's lack of remorse for Spider's death. They track down Kitty and learn they have been paid to bring more people to the fair, with some having gone missing. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

Knock Knock Bill and five students (Shireen, Pavel, Harry, Felicity and Paul), seeking to room together, take an offer by an elderly Landlord for a large mansion at very low cost, as long as they do not enter the tower. Bill gets the Doctor to help with her move. The Doctor insinuates himself among Bill's friends, to Bill's consternation, and is troubled by the numerous noises the house makes. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

Oxygen The Doctor, Bill and an angry Nardole travel in the TARDIS to follow a distress call to a deep-space mining station. When the TARDIS is jettisoned by the station's computers, the trio are forced to wear "smartsuits", robotic spacesuits capable of independent operation tied to the station. The suits are also the only source of oxygen, as the mining company does not provide an oxygen atmosphere inside the station, and every activity is measured in breaths. The surviving crew warn them that some suits have received instructions to "deactivate" their "organic components", killing the wearer via an electrical discharge but remaining autonomous. This signal can be carried by touch, which has caused most of the crew to be turned into zombies, enslaved to the suits' programming. The Doctor and the others plan to walk outside the station to an uncompleted portion not updated in the computer systems to hide. Bill's suit malfunctions during depressurisation and forces her to remove her helmet. To save her, the Doctor gives her his helmet as they spacewalk. He survives the vacuum of space, but has gone blind from the ordeal. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

Extremis The Doctor remains blind ("Oxygen") and wears his sonic sunglasses to provide limited sight while hiding his condition from Bill. He receives an email entitled Extremis that he views through his glasses.

The Doctor is met by the Pope and members of the Holy See to help deal with a recently-translated text called the Veritas, that causes readers to commit suicide. The Doctor takes Bill and Nardole to a secret library inside the Vatican. They find that a translation of the Veritas has been emailed to CERN. Bill and Nardole discover a portal leading to a hub of other portals, linked to CERN and the White House, among other places. Meanwhile, the Doctor temporarily regains his sight using Time Lord technology and tries to read Veritas, but is forced to flee into a second portal with the translation when the skeletal, corpse-like Monks appear. He is unable to read the Veritas before again losing his sight. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

The Lie of the Land The Monks are rulers of the Earth, and appear to have been on Earth for millions of years, guiding human development. Bill and a few others are aware of the truth: the Monks have only been present on Earth for six months. Those who hold this view are imprisoned for "memory crimes". The Doctor appears on television praising the Monks' guidance over humanity.

Bill keeps herself grounded in reality by imagining that she is talking with her long-dead mother, based on pictures the Doctor gave her. Nardole, also aware of the truth, locates Bill and helps her to find the prison hulk where the Doctor is thought to be a captive. Inside, after a team of commandoes swarm inside, the Doctor tells Bill he is cooperating willingly with the Monks, believing that humanity was doomed without their guidance. Bill becomes distraught and shoots the Doctor, who appears to begin regenerating, but quickly stops. The entire scenario is revealed to have been a test by Nardole, the Doctor and the team, to make sure Bill was not under the influence of the Monks. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

Empress of Mars On Earth 2017, NASA finds the words "God save the Queen" made of rocks buried under the ice cap of Mars. The Doctor, Bill and Nardole venture to Mars in 1881 to investigate, and they discover that the planet is occupied by human soldiers from Victorian Britain. Nardole goes back into the TARDIS, but it departs for unexplained reasons, returning to the university in present day. Nardole asks Missy for help getting back.

The humans have befriended an Ice Warrior they have named Friday. Captain Catchlove says they rescued Friday from his crashed spaceship while on patrol in Africa. In exchange, Friday allowed the soldiers to use his species' technology to travel to Mars, establish a small breathable atmosphere within a cavern, and mine the planet. The Doctor surmises that Friday is using them to access his hive. They soon unearth the tomb of the Ice Empress. Despite Colonel Godsacre's order to not approach it, one guard inadvertently revives the Ice Empress, Iraxxa. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

The Eaters of Light The Doctor and Bill, disagreeing about the fate of the Ninth Legion of the Imperial Roman army, travel in the TARDIS along with Nardole to the 2nd century in Scotland to prove the other wrong. Bill goes her own way to find the Legion, while the Doctor and Nardole look for their dead bodies.

Bill encounters some of the Legion's soldiers hiding underground, the TARDIS' translation circuits helping her communicate with them. The soldiers are hiding from a "Light Eating Locust" that seems drawn to any light source, killing those in its path. Meanwhile, the Doctor and Nardole discover the boneless corpses of the remaining Legion. They later come across a Pict tribe guarding a cairn and waiting for Kar, their leader and the "Guardian of the Gate". The Doctor impatiently enters the cairn, passing into an interdimensional portal full of creatures feeding off a light source. He comes out seconds later, but finds that more than two days have actually passed. Kar explains that once a generation, a warrior of their tribe goes through the cairn to defeat an "Eater of Light", but with the invading Roman army, she allowed one to escape to fight them. The Doctor warns her that unless they can get the creature back into the portal and close it, more of its kind will escape and consume the sun and all the stars in the universe. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

World Enough and Time In a cold open, the Doctor stumbles out of the TARDIS into a snowscape and collapses to his knees. He begins to regenerate, repeatedly saying "no".

The Doctor, testing to see if Missy can turn good drops her, Bill and Nardole off on a colony spaceship facing a black hole in the hopes of saving it. Missy introduces herself as 'Doctor Who' which she claims is The Doctor's real name when The Doctor says it isn't. They are met by a blue skinned humanoid named Jorj who demands to know which one of them is a human. Bill confesses and Jorj shoots her to make sure that the creatures that are on board the ship don't come for her. Figures with bandaged faces in hospital gowns collect her body, and, using a voice synthesiser, claim thatbthey will fix her and not return. The Doctor explains that due to the lower part of the ship facing away from the black hole the timezone is faster than the one they are in. He also states that the creatures on board the ship are the descendants of the crew who went to the lower part of the ship when it got dragged towards a black hole and needed to be reversed. The Doctor then knocks out Jorj so that he and the others can follow Bill. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

The Doctor Falls Aboard the colony ship trapped in the event horizon of a black hole, the Doctor finds Bill has been converted into a Cyberman. The Master and Missy capture him, but the Doctor had earlier surreptitiously reprogrammed the Cybernet to target Time Lords as well, forcing them to flee. Nardole arrives in a commandeered shuttlecraft to rescue them. The Doctor, however, is electrocuted by a Cyberman, but is saved by Bill.

They evacuate to a higher level of the ship containing a solar farm populated by children and a few adults fighting off early Cybermen prototypes. The Doctor recovers, but suppresses the early signs of regeneration. Bill initially remains unaware of her transformation, her strong mind acting like a perception filter, until one of the children inadvertently reveals the truth to her. Bill sheds a tear, which the Doctor calls a hopeful sign. Missy and the Master discover a camouflaged lift, a possible escape route. But when they call for it, an upgraded Cyberman arrives, which the group destroys. The Doctor warns that the time dilation affords the Cybermen more time to evolve and strategize. Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'

2017 Christmas Special Episode Description Read More! (Caution spoilers!) Download the closed captions for this episode! Right click and 'save as'