UNIT arrives at Sarah Jane's door with terrible news: the Doctor is dead, his body brought to Earth by alien undertakers called the Shansheeth. Sarah Jane refuses to believe that her friend is gone for good, but she nonetheless agrees to travel to a UNIT base for the Doctor's hastily-assembled funeral. She isn't the only skeptic: also in attendance is Jo Jones, Sarah Jane's predecessor aboard the TARDIS, who is equally convinced that the Doctor is still alive. But when Clyde discovers that he and the Doctor share an unexpected connection, it's up to him, Rani and Jo's grandson Santiago to uncover the Shansheeth's scheme.

David Tennant's appearance as the Tenth Doctor in 2009's The Wedding Of Sarah Jane Smith had provided a tremendous ratings boost to The Sarah Jane Adventures. Discussion soon ensued about the possibility that the subsequent season might see the Bannerman Road gang meet the Eleventh Doctor as played by Matt Smith, who was taking over from Tennant on New Year's Day 2010. This concept was assigned to lead writer Phil Ford as one of two stories he was planning to write for the 2010 season -- with the other ultimately becoming The Vault Of Secrets -- and replaced an idea about Mr Smith creating a humanoid avatar of himself to fight a crystalline entity. It was proposed that the new serial could involve the Doctor's purported funeral, since this would keep the Time Lord off screen until the Episode One cliffhanger, in keeping with the structure of The Wedding Of Sarah Jane Smith.

Executive producer Russell T Davies was concerned that Smith's availability might severely restrict the Doctor's screen time. As such, in December 2009, he suggested that the Doctor's apparent demise should draw the attention not only of Sarah Jane, but also one or more additional established companions. In particular, Davies felt that Jo Grant, played by Katy Manning, was an appropriate character to revisit. Jo was Sarah Jane's predecessor on Doctor Who, and Manning's tenure on the show -- three seasons from 1971 to 1973 -- was comparable to Elisabeth Sladen's. As such, Jo offered a similar nostalgic appeal, and was a character known to Sarah Jane. In her final adventure, The Green Death, Jo had married ecologist Clifford Jones, with whom she would later travel down the Amazon in search of a rare fungus. Subsequent Doctor Who tie-in media had speculated on a grim fate for Jo's marriage and mission, but Davies was determined that The Sarah Jane Adventures would portray Jo's later life in a much more positive light. Although Manning had relocated to Australia in the late Seventies, she had recently decided to spend more time in the United Kingdom. As such, she was delighted to accept the offer to bring Jo back to television.

Executive producer Nikki Wilson suggested that Russell T Davies should write the Eleventh Doctor/Jo story himself

Meanwhile, changes were afoot for The Sarah Jane Adventures following the BBC's decision to pair the production of its fourth season with the first half of season five. It was agreed that Ford's focus would be shifted to the latter, meaning that a new writer would have to be found for the Eleventh Doctor/Jo story. Executive producer Nikki Wilson contacted Davies and suggested that he should take on this assignment himself. Davies had not provided a script for The Sarah Jane Adventures since his collaboration with Gareth Roberts on the debut episode, 2007's Invasion Of The Bane. As such, he would have his first chance to write for Clyde and Rani, who were later additions to the programme. It would also provide Davies with the opportunity to tackle the Eleventh Doctor, since he had decided not to write for Doctor Who now that his time as showrunner was over.

Having agreed to Wilson's suggestion, Davies turned to Steven Moffat -- his successor on Doctor Who -- for advice on writing for Smith. For his part, Moffat was delighted by the prospect of Smith appearing in The Sarah Jane Adventures. Indeed, he encouraged Davies to incorporate a cameo appearance for the Doctor's new companion, Amy Pond. However, the production budget for The Sarah Jane Adventures precluded the hiring of actress Karen Gillan. Davies' serial was eventually known as Death Of The Doctor -- a title he had previously considered for the second episode of Tennant's final story, The End Of Time. Notably, it featured the first visit to an alien planet ever depicted in The Sarah Jane Adventures; previously, the programme had ventured no farther afield than an orbiting spaceship.

Although Death Of The Doctor was intended to be the 2010 season's fifth serial in both the recording and broadcast schedules, it was moved up to the third spot due to Smith's availability. Consequently, it was paired with The Empty Planet -- originally the third story, and now bumped to fourth -- to form the year's second recording block. The director would be Ashley Way, who was new to The Sarah Jane Adventures but who had recently made The Hungry Earth / Cold Blood for Smith's first Doctor Who season; he would therefore be familiar with the Eleventh Doctor. One of the Shansheeth voice actors was David Bradley, who was perhaps best known for playing the curmudgeonly Hogwarts caretaker Argus Filch in movies since 2001's Harry Potter and The Philosopher's Stone. He would later portray the First Doctor in several Doctor Who stories beginning with 2017's The Doctor Falls, filling the void left by the late William Hartnell.

On April 26th, 2010, production began on Death Of The Doctor with Tommy Knight's brief return as Luke Smith. It was shot on the set for his Oxford dorm room at the programme's regular studio facilities in Upper Boat. Bannerman Road scenes were recorded on Clinton Road in Penarth on the 27th; this marked Manning's first work on Doctor Who in thirty-seven years -- almost to the day! Filming on April 28th began at the Millennium Stadium in Cardiff, for sequences in the bedrooms and corridors of the Unified Intelligence Taskforce (UNIT) base. This was followed by the exterior view of the base, which was captured at the Cemex quarry in Taff's Well. The 29th and 30th were spent back at Upper Boat, and concentrated on material in the funeral chamber.

Smith joined the cast of The Sarah Jane Adventures at Upper Boat on May 3rd, with the focus being scenes outside the funeral chamber doors. It was the first time that Smith had been back in front of the cameras as the Doctor since completing his initial season of Doctor Who on March 20th; in the interim, he had spent time in the United States investigating career opportunities in Hollywood. Smith had to sport a plain shirt for Death Of The Doctor, due to the limitations of the cameras used for The Sarah Jane Adventures. On May 4th, Trefil Quarry in Tredegar posed as the Wasteland of the Crimson Heart. The 5th and 6th brought cast and crew back to the Millennium Stadium for more bedroom and corridor scenes, as well as those at the rocket gantry.

Smith's final day on Death Of The Doctor was a busy May 7th at Upper Boat, when the recording schedule included the sets for the ventilation shafts, the ruined funeral chamber, the TARDIS console room and Sarah Jane's attic. Way then concentrated on The Empty Planet, although two more days at Upper Boat were scheduled to conclude principal photography on Death Of The Doctor. May 17th dealt with sequences in the ventilation shafts, the Groske lair and the attic, followed by more action in the attic and the funeral chamber on the 21st. Inserts on the funeral chamber set were later taped at Upper Boat on June 17th.

Death Of The Doctor was an enormous ratings success for CBBC, with the broadcast of Episode Two on October 26th watched by 960,000 viewers -- a new record for the channel. Unusually, though, the largest audience for the serial came in the form of a Christmas Morning omnibus repeat on BBC One, when an audience of more than one and a half million tuned in as they counted down to that year's Doctor Who festive special, A Christmas Carol.

• Doctor Who Magazine Special Edition #28, 13th July 2011, “Episodes 4.5/4.6: Death Of The Doctor” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who Magazine Special Edition #32, Autumn 2012, “Episodes 5.5/5.6: Meet Mr Smith” by Andrew Pixley, Panini UK Ltd.