A meteor crashlands in 1988 Windsor, carrying a mysterious statue called Nemesis. It was fashioned in 1638 by the wicked Lady Peinforte from a living metal called validium, which was once Gallifrey's last line of defence. Two artefacts are required to activate the Nemesis statue: its bow, now in the possession of a Neo-Nazi called De Flores, and its arrow, which Lady Peinforte has transported through time to 1988. But De Flores and Peinforte aren't the only ones whom the Doctor and Ace must stop from obtaining the validium: the Cybermen have also arrived, determined to seize the power of Nemesis for themselves.

In early 1987, Doctor Who script editor Andrew Cartmel alerted his BBC colleagues that he was actively recruiting new writers to the programme. Having steered Ben Aaronovitch in Cartmel's direction -- eventually resulting in Remembrance Of The Daleks, the first story of Season Twenty-Five -- script editor Caroline Oulton likewise encouraged Kevin Clarke to submit ideas for Doctor Who. Although he was still in the process of establishing himself as a screenwriter, Clarke was not a fan of science-fiction, and only reluctantly met with Cartmel in March. Nothing came of this discussion but, when Clarke had little success securing work elsewhere, he made contact with Cartmel again in September.

Clarke's original idea was a standard Doctor Who adventure, whereas the script editor was eager for his writers to blaze new territory. However, the conversation impressed Cartmel enough that, later in September, he asked Clarke to develop a three-part adventure. It would be made entirely on location, and would serve as a celebration of Doctor Who's twenty-fifth anniversary on November 23rd, 1988. Central to this narrative would be the idea of a meteor with a baleful effect on the Earth's history. With Cartmel's input, it developed into a weaponised silver figure named Nemesis, after the Greek goddess of retribution.

At one point, Kevin Clarke wanted to reveal that the Doctor was God

Another crucial element stemmed from Cartmel's efforts to reintroduce an aura of mystery into Doctor Who, which aligned with Clarke's interest in the question of the Doctor's identity. Indeed, at one point, Clarke wanted to reveal that the Doctor was God -- or, at least, a god-like figure who walked amongst mortals, but sometimes let events run away from him. However, producer John Nathan-Turner balked at the introduction of such overtly religious connotations into the series. On the other hand, it was Nathan-Turner who suggested that the Cybermen were natural villains to appear in a silver anniversary adventure. For his part, Clarke had hoped to use the Daleks, but they had already been earmarked for Aaronovitch's serial.

The first episode of “The Harbinger” was commissioned on November 17th. Clarke incorporated several of his own interests, including jazz music and Jacobean drama. The latter inspired Lady Peinforte, whose name came from the seventeenth-century torture peine forte et dure (literally, “long and hard trauma”) in which increasingly heavy weights were placed on the body. The Nemesis statue drew upon Adolf Hitler's obsession with the Spear of Destiny, the legendary lance described in the Bible as having pierced the side of the crucified Jesus, which was now reputed to bestow great powers upon its bearer. This suggested the inclusion of the Neo-Nazi faction in “The Harbinger”, while De Flores' name was a reference to a murderous servant in the 1622 tragedy The Changeling by Thomas Middleton and William Rowley. Meanwhile, the man to whom Richard owed a debt was given the surname of Ian Briggs, who had written 1987's Dragonfire.

The formal commission for Episodes Two and Three on January 20th, 1988 still described the serial as “The Harbinger”, but it was around this time that it was retitled “Nemesis”. Late changes saw the living element makarianite renamed validium, as well as the introduction of Ace's ghetto blaster, which took the place of the TARDIS scanner and eliminated the need for any studio recording. The American tourist was conceived as the male Milton P Remington. Nathan-Turner hoped to interest Larry Hagman, who starred as tycoon JR Ewing in the American soap opera Dallas; he had been put in touch with Hagman's representatives by Kate O'Mara, who played the Rani, and who had spent a year on Dynasty, a rival Hollywood soap opera. When Nathan-Turner's pursuit of Hagman didn't pan out, the role was rewritten as the female Miss Hackensack, and offered to Tony Award-winning actress Dolores Gray.

John Nathan-Turner hoped that a cameo role in Doctor Who might appeal to Prince Edward, the Earl of Wessex

Another individual whom Nathan-Turner hoped to attract to “Nemesis” was Prince Edward, the Earl of Wessex and third son of Queen Elizabeth. Edward was a fan of the entertainment industry and was then working as a production assistant for famed playwright Andrew Lloyd Webber; Nathan-Turner hoped that a cameo role in Doctor Who might appeal to him, especially given the Windsor Castle setting of “Nemesis”. However, Edward's duties with Webber's Really Useful Theatre Company precluded his involvement in the serial, and he was replaced in the script by his mother, who would be portrayed by an imitator. Nathan-Turner was also disappointed to learn that his request to film at Windsor Castle itself was denied, since permission to do so was only granted to documentary projects. Yet another frustration for the producer came when his proposal for additional funding for “Nemesis”, in view of its celebratory status, was rejected by the Controller of Programmes for BBC One, Jonathan Powell.

By the middle of May, Clarke's adventure bore the expanded title Silver Nemesis. It would be directed by Chris Clough alongside the studio-only The Happiness Patrol, much as Clough had made the tandem of Delta And The Bannermen and Dragonfire the year before. Cast as De Flores was Anton Diffring. The German film star, known for movies such as 1968's Where Eagles Dare, disliked the scripts, which he found confusing. Nonetheless, he took the role because it meant that he could watch coverage of the Wimbledon tennis tournament, which was unavailable at his residence in the south of France. Also amongst the anniversary adventure's cast were two links to Doctor Who's first season: Fiona Walker (Lady Peinforte) had made her television debut in The Keys Of Marinus, while Leslie French (the Mathematician) had been considered for the role of the First Doctor.

Pre-production on Silver Nemesis was complicated when the discovery of asbestos at BBC Television Centre in White City, London forced the rearrangement of the recording dates for the preceding story, The Greatest Show In The Galaxy. As a result, the availability of Sylvester McCoy and Sophie Aldred for rehearsals on Silver Nemesis was severely limited. Indeed, Gray became confused after mistakenly assuming that assistant floor manager Lynn Grant -- who was reading Aldred's lines in her absence -- was actually playing Ace.

Chris Clough and his team were set badly behind schedule at their first location, Greenwich Gas Works

The stars' lack of preparation was one of several factors which helped to set Clough and his team badly behind schedule at their first location, Greenwich Gas Works in Greenwich, London. Filming there took place from June 22nd to 24th for material at the Nemesis statue's landing site and in the hangar. The slow progress played havoc with Clough's plans, causing some shots to be abandoned, while others were rewritten on the spot. For instance, although the extras playing the Cybermen's servitors -- referred to as the Walkmen -- were unavailable on the 24th, Clough was left with no choice but to record some of the scenes in which they were intended to appear. Meanwhile, the director staged the Episode One cliffhanger to show the Cyberman ship landing, whereas it had been Clarke's intention that the vessel was already present, invisibly, and was only now revealing itself.

For the sequence in which the policemen were gassed, visual effects assistant Mike Tucker suggested using the silverfish-like Cybermats, which had not been seen since 1975's Revenge Of The Cybermen. He went as far as building a new Cybermat prop, but Cartmel disliked the creatures and the notion was dropped. Another idea conceived for Silver Nemesis but not ultimately used was the presence of a specially-adapted Communications Cyberman, reminiscent of the Cyber Director from 1968's The Invasion. However, there were concerns that it would seem too similar to the Special Weapons Dalek in Remembrance Of The Daleks, a serial with which Silver Nemesis already had much in common.

Production resumed in Arundel, West Sussex from June 26th to 30th. The first four days were spent on the grounds of the eleventh-century Arundel Castle, which stood in for Windsor Castle. On the 27th, several tourists were baffled by the appearance of a portrait which was not mentioned in the castle guidebook. In fact, it was a creation of the Doctor Who design team, and depicted Ace in the style of Thomas Gainsborough. In Clarke's original conception, the time travellers instead came across a statue of Ace.

June 27th was also the day that a number of familiar faces returned to Doctor Who to make cameo appearances as tourists. This was intended as a salute to Nathan-Turner: the producer believed that he would be leaving the programme at the end of the season and, at this point, Silver Nemesis was planned to be the last story of the broadcast schedule. The lone actor in the group was Nicholas Courtney, who had played Brigadier Lethbridge-Stewart since the Sixties; he had not appeared in Doctor Who since 1983's The Five Doctors. Others in the crowd included directors Andrew Morgan, Peter Moffatt and Fiona Cumming, writer Graeme Curry, production manager Ian Fraser, and production unit manager Kathleen Bidmead. Anthony Ainley (the Master) and writer Stephen Wyatt had hoped to participate, but were ultimately unable to attend. Also involved was Clarke himself; in other scenes, he played a pedestrian while Lady Peinforte and Richard wandered the streets of Windsor, and a motorist who passed the hitchhiking Peinforte.

Cast and crew shifted to the town of Arundel itself on June 30th to film various street scenes, including all those involving the American tourist. Gray had disapproved of the name Miss Hackensack, and so the character was now known as Mrs Remington. Early in the day, Gray was badly upset when she discovered that she had left a bag containing expensive jewellery on the street where she had been collected. Happily, the bag and jewels were found and couriered to her at Arundel. Clough's team next moved to St Mary's House and Gardens in Bramber, West Sussex on July 1st. The fifteenth-century inn was the venue for material in Lady Peinforte's garden and study, as well as its twentieth-century incarnation as a tea room. On July 2nd, another West Sussex location was a private residence called Casa Del Mar in Goring-by-Sea, which served as De Flores' South American retreat.

Finally, on July 5th, Black Jack's Mill Restaurant in Harefield, London provided the garden where the Doctor and Ace listened to the jazz concert, as well as the riverbank into which they dove to make their escape. Clarke was delighted to learn that Courtney Pine -- who had risen to prominence with his 1986 debut album Journey To The Urge Within -- had agreed to appear in Silver Nemesis. Clarke was an admirer of the musician's work, and had written these scenes with Pine in mind, in the hope that they might meet. As it happened, Pine was a fan of Doctor Who, and convinced his bandmates to participate.

A subplot was deleted in which Karl appeared to betray De Flores to the Cybermen

In part because of the limited rehearsals, the original edit of Silver Nemesis proved to be much too long. Various elements were lost or truncated, most notably a subplot in which Karl appeared to betray De Flores to the Cybermen, who planned to convert both men. As written, De Flores' attempt to get away by using gold dust was foiled as part of this ruse; Karl later freed him once the Cybermen were lulled into a false sense of security and had left them virtually unguarded. All that survived of this story strand was the gold dust escape -- now made to seem successful -- and some brief glimpses of De Flores wearing Cyber-headphones.

As it transpired, Silver Nemesis was not the final story of Season Twenty-Five after all. Nathan-Turner was insistent that Episode One should be broadcast on November 23rd, but a four-week delay to the start of the season -- due to coverage of the Summer Olympic Games in Seoul, South Korea -- meant that The Greatest Show In The Galaxy would now follow it in the transmission order. Unusually, Episodes Two and Three aired in New Zealand on November 25th, as part of a TVNZ screening of the entire adventure. This marked just the second occasion on which a Doctor Who episode premiered outside the United Kingdom; the first instance had been the twentieth-anniversary special, The Five Doctors.

• Doctor Who Magazine #244, “Archive: Silver Nemesis” by Andrew Pixley, Marvel Comics UK Ltd.
• Doctor Who Magazine Special Edition #10, 13th April 2005, “Doctorin' The Tardis” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #45, 2015, “Story 150: Silver Nemesis”, edited by Mark Wright, Hachette Partworks Ltd.
• Doctor Who: The Eighties by David J Howe, Mark Stammers and Stephen James Walker (1996), Virgin Publishing.
• Doctor Who: The Handbook: The Seventh Doctor by David J Howe and Stephen James Walker (1998), Virgin Publishing.
• In·Vision #98, September 2001, “Production” edited by Anthony Brown, Cybermark Services.