The Master has stolen the TARDIS, but the Doctor, Martha and Jack follow him back to modern-day Earth using Jack's vortex manipulator. Arriving months after their enemy, they discover that he has assumed the name Harold Saxon. Using the Archangel network of satellites, he has been subtly manipulating human minds, and has now been elected Prime Minister! Tracking the Master to an aircraft carrier called the Valiant, the Doctor is horrified to discover that he's transformed the TARDIS into a Paradox Machine. Soon, only Martha remains free as the Master unleashes the psychopathic Toclafane on the Earth...

After being tasked with the revival of Doctor Who in 2003, executive producer Russell T Davies developed a number of ideas, not all of which he put to immediate use. Amongst those he kept in reserve was a race of monsters which would take the form of small, flying spheres. Possessing the personality of a sadistic child, they would in fact be horribly-mutated humans from the end of time, and so Davies dubbed them the Human Spheres, or simply the Spheres. They were nearly added to 2005's Dalek when the BBC temporarily lost the rights to use the Daleks themselves, and to 2006's The Satan Pit when concerns arose over the manifestation of the Beast. In both cases, however, other solutions were found and the Spheres remained on the shelf. Finally, Davies decided that the creatures should appear as part of the climax to Season Twenty-Nine. They were now called the Roclafane; this later became the Toclafane, to avoid confusion with the Racnoss from the 2006 Christmas special, The Runaway Bride.

Meanwhile, Davies had decided that the Master would feature prominently during the latter stages of Season Twenty-Nine. The Time Lord villain would be reintroduced in episode eleven, Utopia, which would effectively serve as a prologue for the two-part season finale. Having already examined a well-meaning, if flawed, Prime Minister in the form of Harriet Jones -- as played by Penelope Wilton in 2005's Aliens Of London / World War Three and The Christmas Invasion -- Davies was now eager to explore what would happen if the Prime Minister were a truly malevolent figure such as the Master. His alias, Harold Saxon, reused one of Davies' favourite surnames; he had unsuccessfully developed a soap opera called Saxon House during the mid-Nineties. Davies' interpretation of the Master was influenced by the 2005 Rogue Traders song Voodoo Child, and he asked script editor Simon Winstone to clear its use in the story even before he had begun writing the scripts. Indeed, Voodoo Child's lyric, “Here it comes, the sound of drums,” provided the first episode with its title: The Sound Of Drums.

Another major element of the finale would be the conclusion of Martha Jones' character arc

Another major element of the finale would be the conclusion of Martha Jones' character arc, and her temporary departure from Doctor Who. As Season Twenty-Nine had evolved, a significant theme of Martha's development had been her unrequited love for the Doctor. During the second half of 2006, Davies had come to realise that this aspect of her personality would become stale if it were to carry over into the 2008 episodes, but it would be a cheap compromise if her feelings simply evaporated between seasons. He therefore decided to give Martha a break from travelling in the TARDIS, with a view to bringing the character back -- a little older and wiser -- partway through Season Thirty. In the interim, Martha would appear in several episodes of the spin-off series Torchwood.

The Master's survival had initially been foreshadowed by a cryptic message which the Doctor received from the enigmatic Face of Boe in Season Twenty-Nine's third episode, Gridlock. It had previously been established that the Face of Boe was a very long-lived entity, having been active in both the year 200,100 in The Long Game from 2005, and almost five billion years later in stories like Gridlock. This was also true of Captain Jack Harkness, who had gained immortality as a result of his resurrection in 2005's The Parting Of The Ways, and who would be returning to Doctor Who for the last three episodes of Season Twenty-Nine. Consequently, in October, Davies had the idea that the finale should imply that the Face of Boe was actually Jack's future manifestation. This revelation secured the support of Chris Chibnall, the head writer on Torchwood, in which Jack was the main character.

Davies began writing The Sound Of Drums in December 2006. The concluding episode -- eventually known as Last Of The Time Lords -- was then drafted over four feverish days in January 2007. Searching for a suitable humiliation which the Master could inflict upon the Doctor, Davies turned to Neill Gorton and Millennium FX, who handled various monster costumes and prosthetics for Doctor Who. In May, they had won a BAFTA Craft Award, which recognised their work transforming comedian Paul Whitehouse into an elderly man for his programme Help, and Davies confirmed that they could likewise give David Tennant the appearance of decrepitude.

The Archangel satellite network was inspired by the Master's talent for hypnosis

As in Utopia, Davies wanted to use The Sound Of Drums / Last Of The Time Lords to compare and contrast the Doctor and the Master. He created Lucy Saxon to fill the role of the Master's “companion”, with his abusive demeanour standing in sharp relief to the Doctor's nurturing and self-sacrificing attitude towards his friends. Similarly, Davies incorporated characteristics of previous Doctors into the Master's behaviour, such as a fondness for jelly babies, which had been a trait of Tom Baker's Fourth Doctor. Earlier Masters also influenced the latest incarnation. The Archangel satellite network -- originally dubbed Angel One -- was inspired by the Master's talent for hypnosis, established during his very first appearance in 1971's Terror Of The Autons. The character's fascination with the preschool-oriented programme The Teletubbies hearkened back to 1972's The Sea Devils, in which the Master was entertained by The Clangers, another children's show. The start of the Master's speech after the Toclafane murdered President Winters -- “Peoples of the Earth, please attend carefully” -- recalled a similar pronouncement in the 1981 serial Logopolis.

Originally, Downing Street played a much larger role in the story, serving as the location for the last of Martha's decoy chemicals. At this stage, Milligan was in fact a traitor, who was killed after betraying Martha to the Master. Davies began to feel that the world of the ravaged Earth deserved greater exploration, and he instead developed the material involving Professor Docherty. Leo Jones was intended to appear in Last Of The Time Lords, welcoming Martha back to Britain and introducing her to Milligan. This had to be changed due to Reggie Yates' limited availability, as a result of which he could spare only one recording day for Doctor Who. Instead, Yates' involvement was restricted to a short segment of The Sound Of Drums; dialogue now referred to Leo working in the Master's slave force under an assumed name, although it was dropped from the final edit. Meanwhile, a more elaborate car chase sequence was excised from The Sound Of Drums, after it was found to place too great a strain on the programme's budget.

As with 42, the agent who interceded with Francine Jones on behalf of Saxon was meant to be the same man introduced in The Lazarus Experiment. This had to be changed when actor Bertie Carvel became unavailable, and Elize Du Toit was cast as a new, female character instead. Vivien Rook was named for journalist Jean Rook, whose opinion columns in the Daily Express were required reading during the Seventies and Eighties. Martha's suggestion that the Doctor and the Master might be brothers -- which the Doctor quickly dismissed -- was Davies' response to a popular and long-standing fan theory which he found rather daft. Dialogue during Jack's departure in Last Of The Time Lords poked playful fun at the John Barrowman voice-over which prefaced each episode of Torchwood. However, its metatextual nature was felt to be too distracting, and it was ultimately removed.

Seasons 27 and 28 had established a tradition of celebrity cameos during their climactic adventures

Seasons Twenty-Seven and Twenty-Eight had established a tradition of celebrity cameos during their climactic adventures. The Sound Of Drums / Last Of The Time Lords was no different, with various personalities present to offer fictional endorsements of Harold Saxon. They included Sharon Osbourne, host of the The X Factor and star of The Osbournes alongside her husband, heavy metal icon Ozzy Osbourne; pop group McFly, which had recently dethroned the Beatles as the youngest band ever to debut an album at Number One in the UK charts, with 2004's Room On The 3rd Floor; and Ann Widdecombe, Conservative MP and presenter of The Widdecombe Project.

The Sound Of Drums / Last Of The Time Lords formed the eighth and final block of the Season Twenty-Nine production schedule. The director assigned to the serial was Colin Teague, who had already made Ghost Machine and Greeks Bearing Gifts for Torchwood, as well as Invasion Of The Bane for The Sarah Jane Adventures. Much like Doomsday the previous year, the final few pages of the script for Last Of The Time Lords were circulated only to essential personnel. This was an attempt to avoid spoiling the cliffhanger ending -- setting up the 2007 Christmas special, Voyage Of The Damned -- in which the TARDIS apparently collided with the RMS Titanic, the legendary passenger liner which capsized in the North Atlantic after striking an iceberg on April 15th, 1912.

Filming began on February 7th at Doctor Who's usual studio facilities in Upper Boat. With the help of a green screen, Tennant's performance as the diminutive, methuselan Doctor was motion-captured for computer animation. On the 9th, the flashback material in Professor Yana's laboratory was taped at Upper Boat, while the segments featuring the various international news anchors were completed at BBC Wales in Cardiff. The first major location for The Sound Of Drums / Last Of The Time Lords was Hensol Castle in Hensol, a fifteenth-century manor house which was remodelled as a castle from the early eighteenth century. It provided areas suitable for the Downing Street state room on February 15th, the cabinet room and Vivien Rook's study on the 16th, and the cabinet room plus the American university dorm room on the 17th. The Toclafane's address to humanity was also recorded there on the latter day, against a black backdrop.

Adjacent houses on Cwrt-y-Vil Road in Penarth served as Francine's and Clive's homes on February 19th. The scene of the mother -- played by Teague's wife, Marjorie -- watching television with her baby was also shot in the latter location. Later that day, Leo received Martha's warning at the Esplanade in Penarth, while a second unit travelled to Buckinghamshire to tape Sharon Osbourne's cameo under the supervision of Susie Liggat, who had produced Human Nature / The Family Of Blood earlier in the season.

Work on February 20th concentrated on the car chase through Penarth; it started outside Francine's house on Cwrt-y-Vil Road, before continuing onto Queen's Road, High Street and Arcot Street. The return of the Doctor, Martha and Jack from the far future was filmed on the 21st at The Friary in Cardiff. Teague then shot Jack's final scene in Roald Dahl Plass, before moving inside the adjacent Millennium Centre for the Master's election victory address. On February 22nd, Martha's car was abandoned at the Maelfa Shopping Centre in Cardiff. Meanwhile, in London, Liggat's second unit recorded McFly's appearance at Universal Music in Kensington, and Ann Widdecombe gave her testimonial at the Houses of Parliament in Westminster. The 23rd was spent at Upper Boat, concentrating on scenes in Martha's flat and the TARDIS console room.

Recording at Upper Boat resumed after the weekend, with material on the Valiant flight deck dominating the agenda from February 26th to March 1st. Part of February 27th was given over to Martha's farewell in the TARDIS. A second unit was also active on March 1st, with Martha escaping from the Valiant to the Wenallt Woods near Caerphilly. Teague's team began March 2nd at University Place in Cardiff, where the time travellers fled Martha's apartment as it exploded. Cast and crew then shifted to the old Nippon Electric Glass site in Cardiff Bay. Work on scenes in the bowels of the Valiant continued there through the 3rd.

Three more days at Upper Boat followed, from March 5th to 7th. The Valiant flight deck set was again Teague's focus but, on the last day, he and a skeleton crew also shot the cliffhanger ending to Last Of The Time Lords on the TARDIS set. The venue on March 8th was Vaynor Quarry near Merthyr Tydfil; here, Martha and Milligan spied on the rocket silos, the Doctor and the Master had their climactic confrontation, and the Master's funeral pyre burned. A late addition to the script was the recovery of the Master's ring by a woman's hand, which actually belonged to production manager Tracie Simpson. Davies had decided to include this shot in order to give future production teams a mechanism by which the Master could be brought back. It became known as “the hand of the Rani” amongst the crew, in reference to the Time Lord villain played by Kate O'Mara on three occasions beginning with 1985's The Mark Of The Rani.

March 9th was the final day on Doctor Who for both Gugu Mbatha-Raw (Tish) and Trevor Laird (Clive)

On March 9th, RAF St Athan provided the airstrip, as well as the exteriors of the factory and Professor Docherty's shed. This was the final day on Doctor Who for both Gugu Mbatha-Raw (Tish Jones) and Trevor Laird (Clive Jones), while Adjoa Andoh had her last performance as Francine Jones for the year. Likewise, Tennant and Barrowman concluded their work on Season Twenty-Nine on the 10th, when a British Rail warehouse on Maindy Road in Cardiff represented the hideout to which the Doctor, Martha and Jack retreated.

Unlike her colleagues, Freema Agyeman still had work to do the following week. First up was Martha's return to Britain, which was filmed on March 12th at Whitmore Beach in Barry. The shots of the old Time Lord and the juvenile Master were also recorded at the same venue. The Time Lord was dressed in the Gallifreyan robes which had been traditional since The Deadly Assassin in 1976; in fact, the headpiece was a prop which had survived from Doctor Who's twentieth-century iteration. On the other hand, script editor Gary Russell suggested that the young Master's outfit should reflect the earlier Time Lord costumes established in 1969's The War Games.

March 13th was the final day at Upper Boat, covering the remaining scenes on the Valiant flight deck and the Master's television broadcast. Some shots of the Master's pyre from March 8th were remounted, including “the hand of the Rani”; Simpson again played this role. The 14th saw cast and crew visiting two Cardiff locations. Cathays Park was the site of Martha's meeting with Professor Docherty in the adventure's coda, while South Luton Place provided the house where Martha told the story of the Doctor, and the slaves invoked the Doctor's name.

On March 15th, Teague was hospitalised after suffering a fall at his home. Graeme Harper, who had just finished 42 and Utopia, made himself available to direct the remaining scenes for The Sound Of Drums / Last Of The Time Lords. This work took him to the NEG site on the 15th and 16th, which were Agyeman's last days as a Doctor Who regular. The location now provided the interior of Docherty's shed, the factory, and the hospital where Milligan worked. The final material required for Season Twenty-Nine was the sequence in the cafe at the end of The Sound Of Drums. It had originally been scheduled for Mac's Cafe in Cardiff on March 1st, but had been postponed and was instead recorded at Forte's in Barry on March 19th.

Although it had helped inspire him, Russell T Davies almost forgot to include Voodoo Child in The Sound Of Drums

Doctor Who's regular lead-in, The National Lottery People's Quiz, aired its extra-length season finale on June 23rd. As a result, The Sound Of Drums was scheduled at 7.15pm that day -- the same time as Utopia the week before, but later than the norm for Season Twenty-Nine. Although it had helped inspire the narrative, Davies almost forgot to include Voodoo Child in the episode. He was reminded only at a late stage by Winstone, who had long since obtained the appropriate clearances, and the song was duly inserted into the final edit.

In light of Doctor Who's continuing success, the BBC consented to a bumper-sized edit of Last Of The Time Lords. It would be screened at 7.05pm on June 30th in a 50-minute timeslot, five minutes longer than usual. A special Doctor Who edition of the quiz show Weakest Link, originally aired on March 30th, was repeated immediately prior to the season finale. With the transmission of Season Twenty-Nine now complete, Doctor Who's place in the BBC One schedule was next occupied on a regular basis by the reality competition DanceX. Meanwhile, Last Of The Time Lords placed seventh in the weekly television ratings chart, giving Doctor Who a hat trick of Top Ten finishes for the year. There seemed little doubt that the viewing public was still eager for the Doctor's next great adventure...

• Doctor Who Magazine Special Edition #17, 22nd November 2007, “Episodes 12 & 13: The Sound Of Drums / Last Of The Time Lords” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #56, 2016, “Story 187b: The Sound Of Drums / Last Of The Time Lords”, edited by Mark Wright, Hachette Partworks Ltd.