The Return of Doctor Mysterio

"The Return of Doctor Mysterio" is an episode of the British science fiction television series Doctor Who. First broadcast on BBC One on 25 December 2016, it is the twelfth Christmas special since the show's revival in 2005. It was written by Steven Moffat and directed by Ed Bazalgette. The episode received generally positive reviews from critics.

The only episode of 2016, it stars Peter Capaldi as the Twelfth Doctor, and is the first to feature Nardole (Matt Lucas), who was introduced in the previous – Christmas 2015 – episode "The Husbands of River Song", as his companion. The episode is set in New York City, and involves the Doctor and Nardole linking with journalist Lucy Fletcher (Charity Wakefield) and a superhero called The Ghost (Justin Chatwin) to combat brain-swapping aliens.

Plot
In New York City on Christmas Eve of 1992, an 8-year-old boy named Grant wakes to find the Twelfth Doctor dangling outside the window of his family's apartment and helps him come into his bedroom. Taking Grant to the rooftop, the Doctor (whom Grant calls "Doctor Mysterio") 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 for a cold he has, 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.

The Doctor returns to New York in 2016 with Nardole, to investigate Harmony Shoal, a multinational research company. They encounter a news reporter, Lucy Fletcher, who is conducting a similar investigation. The group discovers that it is being secretly run by a group of living alien brains that transplant themselves into any living creature they need for their plans. They witness the killing of the company's owner, Mr Brock. Tracked down by Dr Sim, an employee the brains already took over, the group is suddenly rescued by a masked superhero named the Ghost, who afterwards transports Lucy close to her home. Returning to her apartment before her, the Ghost transforms back into Grant, who works for Lucy as a nanny.

Lucy returns and interrogates the Doctor, forcing him to reveal that the alien brains colonise planets by taking control of their prominent leaders, with Earth being their next target. Leaving Lucy to prepare for an interview with Grant's alter ego, the Doctor and Nardole track down the alien's ship in a low orbit and board it via the TARDIS. There, they discover that the ship's reactor is in a critical state and realise from Dr Sim that he intends to drop it on New York. The Doctor realises the city would be vaporised except for the Harmony Shoal building. World leaders would then take shelter in the company's other buildings within each capital city, believing Earth was under attack, allowing the brains to take them over. After Dr Sim lets slip the ship is to be dropped at a designated time, the Doctor forces its descent ahead of schedule.

Ghost and Lucy are captured by the brains during the interview. They plan to transplant themselves into Ghost's body. Ghost flies away, returning as Grant to protect Lucy. Unable to change the ship's course during its descent, the Doctor sends Grant a message requesting his help. Grant manages to stop the alien's ship from crashing into the city, but reveals himself as the Ghost to Lucy in the process. Lucy is won over and Grant takes her in tow as he disposes of the ship. The Doctor alerts UNIT, which shuts down Harmony Shoal, unaware that the alien brain in Dr Sim has escaped within one of their soldiers.

Development
The episode was filmed in Sofia, Bulgaria and Cardiff, Wales. Various sets were built for the episode to match the look of New York City.

The episode was written by Steven Moffat. It contains several references to comic particularly Superman. Grant has roughly the same standard powers of Superman, including flight, super-strength, super-speed, being bulletproof, and possessing X-ray vision, along with other unconventional powers. He gains his abilities from a stellar-powered object (a gemstone made from a star, in the episode), much as Superman gains his from Earth's yellow sun. There is also a reference to the mobile game Pokemon Go.

Promotion
The episode was revealed and the first trailer was shown at the 2016 New York Comic Con on 7 October 2016. A preview clip was shown as part of the Children in Need broadcast on 18 November 2016.

Cinemas
The episode received cinema screenings in Australia and New Zealand on 26 December 2016, in Canada on 26 and 28 December 2016, and in the United States on 27 and 29 December 2016.

Television ratings
The episode had an official rating of 7.83 million viewers in the UK with a 31.2% share, making it the 6th most watched show on Christmas Day 2016. The overnight rating was 5.68 million, a share of 27.1% of the total TV audience. The episode received an Appreciation Index score of 82. It also received 1.7 million viewers on BBCA, was BBC America's top telecast of the year across all key demographics, and was the most talked about Christmas Day television programme on Facebook and Twitter.

Critical reception
"The Return of Doctor Mysterio" received generally positive reviews from critics. On Rotten Tomatoes, 89% of 18 reviews are positive for the episode, with an average rating of 7.9/10. The site's consensus reads "The Return of Doctor Mysterio is a welcome return of Doctor Who after a year's absence, with the added fun of seeing Steven Moffat take a heroic swing at his version of a Superman story."

The Daily Telegraph gave a positive review of five out of five stars and praised the performance of Peter Capaldi and described the episode as having a fun "classic feel". Andrew Billen writing in The Times gave the programme four stars out of a possible five. Billen said that Capaldi was at his warmest and said that Matt Lucas as Nardole brought a "panto brio to an already exuberant episode". The Guardian gave a positive review of The Return of Doctor Mysterio naming the episode "Cosmic baddies are inserting alien brains into world leaders’ heads in the Christmas special. It’s timely, top-of-the-tree fun – and Peter Capaldi and Matt Lucas are a pantomime treat".

IGN said "'The Return of Doctor Mysterio' is a pretty lightweight entry in the Twelfth Doctor's oeuvre, which considering the events of last season isn't necessarily a bad thing. But the different elements of the episode don't come together as smoothly as they could, and the emotional through line for the Doctor is treated mostly as an afterthought" but gave it 7.0 out of 10. The A.V. Club's Alasdair Wilkins gave a "B-" rating, describing it as "jolly" and "goofy".

Home media
The episode was released on DVD and Blu-ray in the United Kingdom on 23 January 2017, with a U.S. release following on 21 February 2017.