Schemes set in motion long ago lead to the resurrection of the Master, albeit in a form that hovers between life and death. He is abducted by Joshua Naismith, an unscrupulous billionaire who needs assistance repairing an alien device called the Immortality Gate. Warned of these events by the Elder Ood, the Doctor prepares to confront his arch-nemesis. As the threads of prophecy pull tighter, unexpected help arrives in the form of Wilfred Mott. But even as the Master schemes to betray Naismith and use the Immortality Gate to achieve unimaginable power, a far greater threat to all of time and space is returning through the dark...

Since 2006, Doctor Who executive producer Russell T Davies had known that his time on the programme would end with a series of specials bridging Seasons Thirty and Thirty-One. For a long time, it was uncertain precisely when the last of these specials would air, although Christmas 2009 and Easter 2010 were the most likely candidates. It was soon clear that executive producer Julie Gardner would depart alongside Davies, and it seemed likely that the final special would see the regeneration of David Tennant's Tenth Doctor, with the actor himself reinforcing the sentiment by the end of 2007. In April 2008, however, this assumption was thrown into doubt when Tennant learned of incoming showrunner Steven Moffat's plans for Doctor Who. He found himself reconsidering his decision to leave in the final special, and instead pondered the possibility of staying for one more year.

Moffat asked Tennant to make a decision quickly, since he needed to start finalising his creative plans for Season Thirty-One. Furthermore, if Tennant decided to remain on Doctor Who, it might mean that the last special would be abandoned. On April 16th, Tennant met with Moffat and Piers Wenger, who would be replacing Gardner as Head of Drama for BBC Wales and as Moffat's fellow executive producer on Doctor Who. Tennant had now reached a firm conclusion: although he was deeply impressed by the direction in which Moffat planned to take Doctor Who, he wanted to enjoy it as a viewer, rather than as the series star. Moffat therefore began planning for a new Doctor.

It was suggested that David Tennant's last special could be replaced by a mini-series to air in Spring 2010

In the wake of Tennant's decision, Davies and Gardner met with Jane Tranter, the BBC's Controller of Fiction, on April 17th. Since it seemed that their lead actor still had an appetite to make more Doctor Who, they suggested replacing the last special with a mini-series to air in the spring of 2010, with Moffat's first season moving to the autumn. Tranter countered with the offer of an epic two-part story, which would be broadcast immediately prior to Season Thirty-One. However, Davies and Gardner argued that space was needed between the Tenth Doctor's farewell and the Eleventh Doctor's debut adventure, in order to deprive neither of the event status that they deserved. Tranter concurred, and instead it was agreed that the two installments could air in January 2010, three months before Season Thirty-One's anticipated Easter premiere.

The expansion of Tennant's finale to two episodes meant that Davies had to abandon an idea he had already been considering. It would have seen the TARDIS materialise on board a spacecraft carrying an alien family; the Doctor would sacrifice his life to prevent a radiation leak and save these ordinary, seemingly unimportant beings. Although Davies liked the notion of the Tenth Doctor's regeneration taking place in such unremarkable circumstances -- as opposed to the blockbuster events that had characterised each of his season finales -- he was concerned that viewers would be deflated by the anticlimax. With twice the amount of screen time now available, however, there was no debate: such a simple idea could not support two hours of television.

Davies decided to salvage only the beginning and end of his original story. The prologue would see the Doctor summoned to the Ood-Sphere, to be warned that the end of his life was imminent; this would tie into Season Thirty's Planet Of The Ood, in which Ood Sigma had prophetically warned the Doctor that his “song must end soon”. The epilogue, meanwhile, would involve the Doctor staving off his regeneration long enough to visit each of his former companions one last time. The rest of the narrative would be much more spectacular, and see the resurrection of the Doctor's Time Lord arch-nemesis, the Master. Although he had killed off the character in Season Twenty-Nine's Last Of The Time Lords, Davies had added a scene in which the Master's ring was retrieved by an unknown woman. At the time, his intention had been to provide a method by which a future writer could resurrect the villain, but he would now make use of the device himself.

Russell T Davies' first instinct was to have the Doctor and the Master swap bodies

On May 1st, John Simm agreed to reprise the role of the Master, forgoing a stage play he had previously been considering. With Simm's involvement secured, Davies set about developing his storyline. His first instinct was to have the Doctor and the Master swap bodies. However, Davies wasn't keen for Tennant to play anybody other than the Doctor during his final story, and he was also mindful that this idea might appear to rehash elements of Season Twenty-Eight's New Earth. By mid-June, he had instead inverted the concept, with the Master using an alien device to take over every being on Earth apart from the Doctor -- possessing them not just mentally but physically as well, so that the Earth would wind up being populated with literally billions of Masters. He considered calling the episode “The Immortality Gate”, in reference to the alien device.

The Doctor's companion during Season Thirty had been Donna Noble, as played by Catherine Tate. The character was written out in the season finale, Journey's End, having lost all memory of her time in the TARDIS. As such, each of the specials was being designed to introduce a one-off companion figure. In early July, Davies struck upon the idea that the Tenth Doctor's final story should see him accompanied by Donna's grandfather, Wilfred Mott, whom Bernard Cribbins had portrayed in several episodes since the 2007 Christmas special, Voyage Of The Damned. Davies knew that Cribbins had played another companion of sorts, Tom Campbell, in the 1966 Aaru Pictures release Daleks: Invasion Earth 2150 AD, which was adapted from the 1964 Doctor Who serial The Dalek Invasion Of Earth. He now found himself excited by the prospect of giving the actor another opportunity to board the TARDIS, something Cribbins regretted that Wilfred had not accomplished to date.

At the Season Thirty wrap party on March 21st, Tate had agreed to return for a cameo in Tennant's final story. Davies had originally intended Donna to appear in the epilogue, giving him a chance to show that she was enjoying a good life despite the tragic circumstances of her departure from the TARDIS. Now he saw a way to write a more substantial part for Tate, but he knew he would have to balance this against the risk of undermining the denouement of Journey's End. This meant that Donna would be kept separate from the Doctor, thereby permitting Wilfred to take on a renewed importance. It would also allow Davies to resurrect an idea he had developed for Season Thirty's Partners In Crime, with Wilfred leading a team of pensioners who operated as a sort of neighbourhood watch for alien activity.

John Simm wanted to draw on Heath Ledger's portrayal of the insane Joker in The Dark Knight

Davies hoped to broaden the scale of the finale by taking the action out of the United Kingdom; in particular, he envisaged location filming in a desert locale to provide a very different backdrop for the Doctor's conflict with the Master. In late July, however, Davies decided that such a setting would better suit Planet Of The Dead, the Easter 2009 special. Towards the end of September, Davies met with Simm to discuss the storyline. Simm indicated that he wanted to draw on Heath Ledger's portrayal of the insane Joker in the recently-released Batman movie The Dark Knight; he also suggested that his hair should be bleached white for his return. This suited Davies' notion that the Master's resurrection would have gone awry. He would be trapped between life and death, even occasionally transforming into a living skeleton, in a scenario inspired by the evil wizard Voldemort of JK Rowling's Harry Potter novels.

In early October, Moffat accepted Davies' invitation to write the final moments of the concluding special, which would introduce the Eleventh Doctor. Around this time, Davies was also pondering the sequence of events that would lead to the regeneration. He had decided that it would involve two linked chambers, one of which must always be occupied. With the contraption about to be flooded by radiation, the Doctor would enter one of the booths to save a technician called Keith who was trapped in the other booth. This was a variation on an element of the alien family narrative which Davies had earlier contemplated. On October 17th, Davies realised that the man whom the Doctor saved from the radiation chamber should, in fact, be Wilfred. This would be the ultimate explanation for the string of coincidences which had always surrounded the two characters.

Meanwhile, discussions were ongoing about the timeframe for broadcasting the two-part adventure. Some thought was given to positioning both episodes on Christmas Day 2009 -- as had previously been done with EastEnders -- only to meet with resistance from the BBC schedulers. Instead, it was suggested that “The Immortality Gate” would air on Christmas Day, followed by the final installment on New Year's Day 2010. Davies was concerned that the Christmas setting he envisaged for the story would seem out of place by the time the adventure concluded, but he eventually decided that he could simply limit any references to the holiday in the second episode.

The Master's goal would be to trap Earth in the Time War in Gallifrey's place

During November, the spectre of budget cuts to the Doctor Who specials was raised as a result of the ongoing global financial crisis. At first, it appeared that the final story might have to consist of two forty-five-minute episodes rather than hour-long installments. Subsequently, consideration was given to dropping the preceding special, The Waters Of Mars, altogether. By the end of the month, however, sufficient funding had been arranged to avert any of these concessions. Around the same time, Davies and Gardner had independently decided that Gallifrey should figure prominently in the final adventure, bringing full circle the Time War arc that Davies had introduced when he revived Doctor Who in 2005. However, Davies was unhappy with his initial idea -- that the Master's ultimate goal would be to trap Earth in the Time War in Gallifrey's place -- and he considered abandoning the plot strand.

Gardner encouraged Davies to find a way to make Gallifrey work and, as 2009 dawned, Davies began formulating a new set of ideas. Around the same time that Matt Smith was announced as the Eleventh Doctor on January 3rd, Davies had developed the idea that the Time Lords would now be villains; that they had been corrupted by the aeons-long Time War, and the Doctor had destroyed them along with the Daleks because they had become equally monstrous. As formal scripting got under way later that month, Davies decided to introduce a mysterious Time Lord Woman whose identity would not be made explicit on-screen, but whom he intended to be the Doctor's mother -- brought back to life during the Time War much as the Master had been. Likewise, the Time Lords would once again be led by their legendary founder, Rassilon. Originally mentioned in 1976's The Deadly Assassin, he had briefly been seen in a ghostly form during the twentieth-anniversary special, The Five Doctors, in 1983.

At this stage, inquiries were being made to ensure that all of the actors who had played the Tenth Doctor's companions would be available to film cameo appearances for the final episode. Davies indicated that if any of them proved unavailable, the epilogue would be truncated to focus only on Donna and the Tenth Doctor's original companion, Rose Tyler. The latter's appearance would be set before the events of 2005's Rose; neither Davies nor Gardner was keen to revisit the parallel universe where the character now lived, given that her story had been drawn to a close in Journey's End. In addition, Davies wanted to retain a sequence in which the Doctor visited the granddaughter of Joan Redfern, the woman he had almost married in Season Twenty-Nine's Human Nature / The Family Of Blood. Davies hoped that the granddaughter could be played by Jessica Hynes, who had portrayed Joan, but he agreed that this scene should also be dropped if Hynes' involvement could not be arranged.

Russell T Davies dismissed a sequence involving American news anchor Trinity Wells as self-indulgent

Davies finished the script for the first episode on February 13th. For a time, it included a sequence at the ruins of HMP Broadfell in which the Doctor actually met Trinity Wells, the American news anchor who had appeared intermittently ever since Aliens Of London in 2005. Davies was eager to give actress Lachele Carl more than just a background appearance in Doctor Who, but he ultimately dismissed the sequence as self-indulgent. For the billionaire, Davies reused the surname Naismith, which he had previously employed for one of the families at the heart of his 1993 serial Century Falls. He also seeded a reference to the character onto an advertisement which appeared in Planet Of The Dead. Naismith's daughter was initially called Alice, but soon became Abigail.

For the scenes where the Naismiths held the Master in restraints, Davies drew upon the 1991 thriller Silence Of The Lambs, in which serial killer Hannibal Lecter was similarly confined. The juddering effect which Davies envisaged accompanying humanity's transformation into the Master was inspired by the special effects seen in the surreal 1990 horror film Jacob's Ladder. In developing the benevolent aliens whose race created the Immortality Gate, Davies was reminded of his fondness for Bannakaffalatta, the cyborg in Voyage Of The Damned. Although it was never stated on-screen, Davies had intended the red-skinned extraterrestrial to be from a race called the Zocci; he now introduced the green-skinned Vinvocci, whom he imagined to be a related species. Meanwhile, the notion of broadcasting both episodes on Christmas Day was briefly -- and unsuccessfully -- resurrected.

As he prepared to begin work on his final Doctor Who script, Davies came up with the idea of making the Time Lords' corruption explicit by revealing that they had entered into an allegiance with the same Daleks they had fought for millennia. However, Moffat was also planning to feature the monsters in Season Thirty-One's Victory Of The Daleks, and he expressed his preference for this to be the first Dalek story in a while. Keen not to undermine his successor's debut season, Davies abandoned the notion.

Davies began writing the Tenth Doctor's final episode on February 24th. Some of the climactic Time Lord material was inspired by Chris Rea's 1989 album The Road To Hell, while the Vinvocci ship was called the Hesperus after Henry Wadsworth Longfellow's 1842 poem The Wreck Of The Hesperus. Wilfred's description of his military service in Palestine was drawn from Cribbins' own experiences, the only difference being that the actual blizzard endured by the actor became a metaphorical blizzard of bullets for Wilfred. Joan Redfern's granddaughter was named Verity Newman -- an homage to Verity Lambert, Doctor Who's first producer, and Sydney Newman, who had instigated the programme's creation in 1963.

A subplot was dropped in which the Doctor tried to convince the “Danes-Master” to rebel against the evil Time Lord

One prominent element dropped from the script was a subplot in which the Doctor tried to convince the “Danes-Master” -- that is, the copy of the Master who had been Danes, the Naismiths' butler -- to rebel against the evil Time Lord. Also eliminated was a joke in which the two Vinvocci would have revealed that they were actually called Shanshay and Shanshay. A baffled Wilfred assumed that they shared the same name, but the Doctor would have been able to discern the subtle difference in pronunciation.

The concluding episode gave Davies the opportunity to include some ideas that he had intended to use in earlier stories. The dogfight involving the Hesperus drew from some of Davies' original plans for Planet Of The Dead. Captain Jack Harkness' scene reinstated two abandoned notions for The Stolen Earth / Journey's End: a scene featuring a cavalcade of Doctor Who monsters reminiscent of the Mos Eisley Cantina sequence in 1977's Star Wars, and the return of Russell Tovey as Alonso Frame, who had originally appeared in Voyage Of The Damned. Davies also decided to reveal Mickey Smith as Martha Jones' husband -- rather than Tom Milligan, the physician to whom she had been engaged during Season Thirty's The Sontaran Stratagem / The Poison Sky -- as a nod to Smith And Jones, the Season Twenty-Nine adventure which had introduced Martha. The Doctor's reference to Donna's late father, Geoff, was included as a tribute to actor Howard Attfield; it had been intended that Attfield would play the role on a recurring basis during Season Thirty, but he had sadly succumbed to cancer soon after the start of production.

Davies completed his first draft on March 5th, although he had long before devised the Tenth Doctor's final lament: “I don't want to go”. In fact, these words had come to him eighteen months earlier, in September 2007, during the scripting of the Season Thirty premiere, Partners In Crime. Later the same day, he received Moffat's additional material for the end of the episode. Davies had expected the new Doctor to utter just a single line, but Moffat had taken the opportunity to write a short monologue. It led directly into The Eleventh Hour, the first story of Season Thirty-One.

Directing the Tenth Doctor's final adventure was Euros Lyn, whose most recent Doctor Who work had come on Season Thirty's Silence In The Library / Forest Of The Dead. He would be joined by producer Tracie Simpson, who had served in the same capacity on Planet Of The Dead. In early March, it was learned that Hynes would be leaving for America imminently, to appear on Broadway for several weeks. Davies was prepared to drop her cameo, and perhaps replace it with a scene involving Elton Pope and Ursula Blake from Season Twenty-Eight's Love & Monsters. However, it was ultimately agreed that the scene could be recorded ahead of the main shoot. As such, the first material recorded for the two-part special was the dying Doctor's meeting with Verity, filmed on March 21st at the Cardiff University branch of Blackwell's Bookshop.

Freema Agyeman's material was carefully scheduled around her commitments to Law & Order: UK

Principal photography got under way at Tredegar House in Newport, which posed as the Naismith estate from March 30th to April 3rd. On April 4th, the first week of production ended at Corus Strip Products in Newport. Inside the factory, Lyn recorded the scene of Wilfred encountering the Woman aboard the Hesperus. Outside, Martha and Mickey tracked the Sontaran, in material that was carefully scheduled around Freema Agyeman's commitments to Law & Order: UK. The alien -- called Commander Jask in the script -- was played by Dan Starkey, who had been Commander Skorr in The Sontaran Stratagem / The Poison Sky.

From April 6th to 8th, a house on Nant-Fawr Road in Cardiff once again served as the Noble residence, as it had throughout Season Thirty. On the last day, material aboard the Silver Cloak's minibus was also taped in the vicinity. On the 9th, Donna's wedding was filmed at St Mary's Church in Marshfield, while the “Guard-Master” found the Whitepoint Star diamond in a nearby field. Another familiar location was Clinton Road in Penarth, which served as Bannerman Road in the spin-off series The Sarah Jane Adventures. On April 10th, the sequence with Sarah Jane and Luke Smith was recorded there and on the adjacent Victoria Road, while Donna's confrontation with the “Chiswick-Masters” took place in a nearby alley.

After the weekend, April 13th wrapped up Tate's involvement with the special, as the Doctor and Wilfred's cafe conversation was recorded at the Kardomah Cafe in Swansea. The Doctor's pursuit of the Master through the wasteland was filmed on the 14th at the Cardiff Docks. On April 15th, scenes outside the old warehouse were taped at Mir Steel in Newport. This was also the day that the BBC formally announced Doctor Who's incoming production team. Joining Moffat and Wenger as an executive producer would be Beth Willis, who had recently produced Ashes To Ashes. Simpson would continue as a producer on Doctor Who but -- in recognition of the programme's extraordinary demands -- she would now partner with Peter Bennett. Bennett had been an assistant director on Doctor Who as far back as 2005's Bad Wolf / The Parting Of The Ways, and he had produced Children Of Earth, the epic story which comprised the third season of spin-off series Torchwood. At the time of the announcement, Bennett was working on the two-part Doctor Who finale as a first assistant director.

Scenes on the Ood-Sphere were next on Lyn's itinerary. Taff's Well Quarry in Taff's Well posed as the planet's surface on April 16th, while Wookey Hole, near Wells in Somerset, served as the Ood Elder's cave on the 17th. The third week of production then wrapped up on April 18th, when several different sequences were completed at the South Wales Traffic Management Centre in Cardiff. They included the newsreader scene with Trinity Wells, plus those set in the headquarters of the Unified Intelligence Taskforce and Chinese Military Command. Meanwhile, with Season Thirty-One now demanding Simpson's attention, Gardner agreed to take on some of her responsibilities for the specials. Far from being burdensome, Gardner was delighted by this turn of events; she had long harboured a desire to shift roles from executive producer to producer of Doctor Who, and she had even considered producing all of the specials herself.

After a day off on Sunday the 19th, a busy April 20th took in a number of locations. In Penarth, the ruins of HMP Broadfell were situated on the corner of Royal Close and Paget Road, while Wilfred first encountered the Woman at St Augustine's Church. Cast and crew then travelled to Cardiff, where Wilfred went Christmas shopping on Wharton Street; Howell's department store was once again dressed as the fictional Henrik's, as in various episodes since Rose. Lyn's team returned to Mir Steel on April 21st and 22nd, for additional scenes in and around the abandoned warehouse and the wasteland. The flashback of Miss Trefusis collecting the Master's ring was also taped there on the latter day. On the 23rd and 24th, production moved to Doctor Who's regular studio home in Upper Boat, where work concentrated on sequences in the Hesperus teleport room. Wilfred's revolver was the same one previously used by Captain Jack.

At Cardiff City Hall, John Simm was required to endure more than 30 costume changes

Following the weekend, April 27th saw material inside HMP Broadfell recorded at Caerphilly Castle in Caerphilly. Upper Boat was again the venue on the 28th, when Lyn shot material in the HMP Broadfell prison cell, the Master's nightmare laughter, and various effects and pick-up shots. Work on April 29th started at Cardiff City Hall for sequences in the White House. To play the transmogrified versions of President Barack Obama and all of the journalists, Simm was required to endure more than thirty costume changes. Most of this work was undertaken by a second unit headed by Gardner, while Lyn and his main unit taped the alien bar scene with Captain Jack and Alonso Frame at Tiger Tiger in Cardiff. As Davies had intended, various monsters put in an appearance, including Slitheen (first introduced in Aliens Of London / World War Three), Sycorax (The Christmas Invasion), Judoon (first introduced in Smith And Jones), Hath (The Doctor's Daughter), and a Graske (from the 2005 interactive game Attack Of The Graske). Visual effects would later add an Adipose (Partners In Crime), although a Vespiform (The Unicorn And The Wasp) was ultimately omitted.

Material on the Hesperus flight deck was recorded at Upper Boat from April 30th to May 2nd, alongside shots in the TARDIS console room on the middle day, and action in the gun turret on the latter day. A notable change was made to the Vinvocci make-up at this point. Originally, the aliens' faces had retained the actors' normal skin tones. It was now decided that they should instead be completely green, with computer tinting used to adjust their appearance in sequences which had already been recorded.

The schedule for the following week spanned May 4th to 8th, and was dedicated to material in the room housing the Immortality Gate. After the weekend, this work continued on May 11th, when Wilfred's TARDIS scene was also filmed, as were various effects shots and inserts. May 12th was a pivotal day, as it was largely given over to recording the Doctor's regeneration. This was the first shot that Smith filmed for Doctor Who; before he did so, Tennant, Davies and Gardner all exited the studio and gave way to Moffat and Wenger, symbolically passing the torch to the new team. The Gate Room set was once again in use on the 13th, this time expanded to include the White Void which formed the link between Gallifrey and Earth. Recording his first material as Rassilon was Timothy Dalton, a noted Shakespearean actor who was perhaps best known as secret agent James Bond in 1987's The Living Daylights and 1989's Licence To Kill. This marked the first time that a Bond actor had appeared in Doctor Who.

May 20th was the final day of David Tennant's Doctor Who tenure

May 14th and 15th saw Lyn's cameras rolling in London. On the first day, the apartment complex at which various residents transformed into the Master was actually Jesson House in Southwark's Rodney Estate. The next day, the Brandon Estate in Kennington posed as the Powell Estate -- Rose and Jackie Tyler's home -- for the first time in three and a half years. Another break over the weekend preceded the start of the eighth and final week of the marathon shoot. May 18th to 20th were spent at Upper Boat, and again focussed on the Gate Room and White Void sets; effects and pick-up shots were also taped on the latter day. The 20th was the final day of Tennant's Doctor Who tenure, with his last performance involving some wire work for the Doctor's jump from the Hesperus. However, Tennant's time as the Tenth Doctor was not truly finished. On May 21st, he recorded a series of Christmas-themed idents for BBC One. The following week, he joined the cast of The Sarah Jane Adventures for The Wedding Of Sarah Jane Smith, which would air in October. His final scene for the spin-off was taped on May 29th.

Meanwhile, Lyn still had more work to do on Tennant's Doctor Who swansong. First, scenes in the Time Lord Citadel and the Black Void were taped at Cardiff's ITV Studios -- formerly HTV Wales Studios -- on May 21st and 22nd. Numerous inserts were completed at Upper Boat on June 3rd. A helicopter shoot was also arranged for the flight to the Naismith mansion, capturing footage of the Severn Estuary and the area of Newport around Tredegar House. Then it was on to post-production, during which Lyn found himself having to make very few trims to either special, in spite of the fact that it had been known all along that Davies' second script was significantly over-length. There had been optimism that the BBC would permit whatever duration the episode was found to require and, in the end, the Doctor Who team received authorisation for a seventy-five-minute time slot.

By late October, the first installment had become known as “The Final Days Of Planet Earth”. For the concluding episode, Davies had earlier considered possibilities such as “The Final Battle”, “The Final Reckoning” or “Death Of The Doctor”; he would eventually repurpose the latter for Death Of The Doctor, a 2010 serial for The Sarah Jane Adventures featuring Smith as the Eleventh Doctor. The last special now became The End Of Time. During November, however, Davies grew to dislike the title he had chosen for the opening episode. He decided that the story would instead be transmitted as Episodes One and Two of The End Of Time, which he thought conveyed an appropriately epic tone. Indeed, it would mark the first time since the programme's 2005 revival that a multi-part Doctor Who story was not accorded individual episode titles.

The broadcast dates for The End Of Time were ultimately fixed as Christmas Day 2009 and New Year's Day 2010. The holiday season saw Doctor Who continue to ride the enormous wave of popularity that had begun to swell during Season Thirty. When accounting for the almost half-million viewers watching on BBC HD, both specials were the most-viewed television broadcasts for their respective weeks, joining Journey's End as the only Doctor Who episodes to accomplish this feat. Although their time on the show had ended -- for now -- the interest that Tennant, Davies and Gardner had engendered in Doctor Who continued to attract new audiences. And with tremendous curiosity now revolving around Smith's Doctor, all signs augured well for the start of a brand new era of Doctor Who starting in the spring...

• Doctor Who Magazine Special Edition #25, 8th July 2010, “The End Of Time” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #62, 2017, “Story 202: The End Of Time”, edited by Mark Wright, Hachette Partworks Ltd.
• Doctor Who: The Writer's Tale -- The Final Chapter by Russell T Davies and Benjamin Cook (2010), BBC Books.