The TARDIS accidentally transports the Mandragora Helix, a malevolent energy being, to Renaissance Italy. The Duke of San Martino has died under mysterious circumstances, and the great thinkers of the fifteenth century are coming to celebrate his son and heir, Giuliano. Desperate to uncover the Helix's plans, the Doctor and Sarah forge an alliance with Giuliano and his friend Marco. But the new Duke's uncle, Federico, schemes to eliminate his nephew. He is assisted by the astrologer Hieronymous, the secret leader of the cult of Demnos -- who has fallen under the sway of the Mandragora Helix.

As plans for Doctor Who's fourteenth season began to come together in late 1975, producer Philip Hinchcliffe decided it was time that the programme returned to the Earth's past. Although script editor Robert Holmes warned that such stories were often tedious and would strain the show's limited budget, Hinchcliffe pointed to the success of Season Thirteen's Pyramids Of Mars, which took place in the 1920s and which Holmes himself had substantially rewritten. The producer now felt that a similar mix of science-fiction elements in an historical milieu would be ideally suited for the new season's premiere adventure.

Inspired by Roger Corman's 1964 film adaptation of Edgar Allan Poe's The Masque Of The Red Death, Hinchcliffe decided that Renaissance Italy would be an appropriate setting. However, he wanted to eschew the approach of many Doctor Who historical serials from the Sixties, by shifting the focus away from the Doctor's encounters with famous individuals like Marco Polo and Emperor Nero. To this end, Holmes met with Louis Marks, whose Planet Of Evil had been much-liked by the production team earlier that year. Holmes knew that he also held a doctorate degree with a specialisation in the history of Renaissance Italy. Before the year was out, Marks had set to work on “Catacombs Of Death”. Since he was a BBC script editor himself, formal clearance had to be sought for Marks' commission; this was finally granted on February 10th, 1976.

Hieronymous was named for a doomsday prophet who briefly rose to power in Florence at the end of the 15th century

Marks drew elements of his narrative from a number of sources. The Mandragora Helix was named after Niccolò di Bernardo dei Machiavelli's 1518 comedy La Mandragola (literally, “The Mandrake”). Hieronymous was a Latinate variant of the first name of Girolamo Savonarola, a doomsday prophet who briefly rose to power in Florence at the end of the fifteenth century. Giuliano and Federico were probably named after Giuliano de Medici and Federico da Montefeltro, two real political figures of the time. Scarlatti and Captain Rossini recalled the Italian composers Alessandro Scarlatti and Gioacchino Rossini.

While Marks was working on “Catacombs Of Death”, Tom Baker was contracted for Season Fourteen. The actor committed to the usual twenty-six episodes on January 23rd, with an option for Season Fifteen as well. Elisabeth Sladen, who had informed the production team of her desire to leave Doctor Who early in the new season, was booked for her last eight episodes on March 19th, around which time her penultimate adventure had been renamed “Doom Of Destiny”.

The director chosen for the season premiere was Rodney Bennett, who had made both The Ark In Space and The Sontaran Experiment for Season Twelve. This would be the final work on Doctor Who for both Bennett and Marks. Given the story's location, Bennett was eager for “Doom Of Destiny” to enjoy Doctor Who's first experience with overseas filming, but Hinchcliffe instead suggested the use of Portmeirion, a Welsh resort village near Penrhyndeudraeth in Gwynedd designed by Sir Clough Williams-Ellis. Portmeirion boasted architecture inspired by the Mediterranean region, and had already featured in many films and television programmes, most notably as the paranoiac Village in Patrick McGoohan's The Prisoner.

The title had changed again by the time production began, to “Secret Of The Labyrinth”. Various alterations had been made to Marks' scripts, most notably the addition of the Episode Three subplot in which a hypnotised Sarah attempted to kill the Doctor. Baker and Sladen had enjoyed a break of more than four months since the end of the thirteenth recording block, just before Christmas. In the interim, Baker had been heavily involved in discussions about a potential feature film called Doctor Who Meets Scratchman, which he was writing with his former co-star, Ian Marter.

Recording for “Secret Of The Labyrinth” in and around Portmeirion took place from May 3rd to 6th. The 7th was kept in reserve in case of delays, but it does not appear to have been required. The first day at Portmeirion saw the debut of a new TARDIS exterior, designed by Barry Newbery; the old prop had collapsed at the end of production on The Seeds Of Doom, the last serial of Season Thirteen. Despite his ninety-two years, Williams-Ellis himself attended parts of the recording. He was very impressed with the ruins Newbery had designed and asked that they be left in place; however, their polystyrene construction meant that they would quickly deteriorate.

Newbery was also called upon to design a new interior for the TARDIS, after Hinchcliffe concluded that the control room set introduced the previous season was too big and cumbersome for recording. He was also frustrated by the technical problems which perpetually plagued the central column and the main doors. Newbery created a smaller, more practical set, dispensing with the clinical whiteness of the original Peter Brachacki design in favour of a wood-panelled look inspired by classic science-fiction author Jules Verne. Its overall configuration remained essentially the same, retaining roundels, a scanner screen and a slimmed-down console. However, the double doors leading outside were replaced by a dark passageway, and the oscillating central column was done away with altogether, much to Bennett's disappointment. The script for Episode One was amended to include the Doctor and Sarah's discovery of the alternative console room.

On May 12th, Sladen's imminent departure from Doctor Who was announced to the press. The next day, she and Baker recorded an LP, Doctor Who and The Pescatons, for release by Argo Records in July. This was the first-ever Doctor Who audio story although, on April 27th, Baker and Sladen had contributed in-character voicework to The Time Machine, an installment of the BBC Schools radio programme Exploration Earth which would air in October. Meanwhile, Marks' serial had become known as “The Curse Of Mandragora” and finally The Masque Of Mandragora.

The recording pattern for Doctor Who changed with the new production slate. The standard two-day blocks which had been commonplace for several years now gave way to sessions which were variously two and three days in length. Furthermore, although the blocks were still held roughly fortnightly, the days of the week on which they fell would be much less consistent. The Masque Of Mandragora was taped at BBC Television Centre Studio 3 in White City, London. The first block took place on May 24th and 25th, one day later than originally scheduled. Here Bennett concentrated on scenes in the palace, with those from the first two installments taped on the 24th, and the remainder on the 25th.

Some work was still being done on the scripts for The Masque Of Mandragora at this point. In particular, a new sequence for Episode Three saw the Doctor explain that Sarah's ability to understand everyone they met was a Time Lord gift that he allowed her to share. It was also decided that the Mandragora energy should not be invisible, as originally planned. Instead, a recording of an industrial sparkler would be superimposed over the relevant footage.

June 8th saw the new TARDIS console room set in use for the first time

The second studio session spanned June 6th to 8th. The first day involved the sequence in the TARDIS corridor, as well as material for Episodes One and Two in the temple, the secret passage, the catacombs and the grotto. Their counterparts from Episodes Three and Four were completed the next day, alongside scenes in the palace dungeon. June 8th saw the new TARDIS console room set in use for the first time; also taped was material in the Mandragora Helix -- a venue described by the script as the Titan Hall -- plus effects work involving the ruined temple.

Doctor Who's fourteenth season was originally intended to debut on October 23rd, and then September 18th, before finally landing on September 4th. In the meantime, the programme's timeslot had seen a variety of occupants, most frequently Walt Disney's The Mouse Factory, but also shows as varied as Jim'll Fix It, Dixon Of Dock Green, Dad's Army and For My Next Trick. With the latter part of Season Thirteen having endured weeks of criticism by watchdogs such as Mary Whitehouse of the National Viewers' and Listeners' Association, the new run of Doctor Who was positioned later in the evening. As such, The Masque Of Mandragora was pushed back by almost half an hour, to 6.10pm (although Episode Two was brought forward by five minutes). This placed it after The Wonderful World Of Disney, and before a new season of Bruce Forsyth And The Generation Game.

• Doctor Who Magazine #287, 9th February 2000, “Archive: The Masque Of Mandragora” by Andrew Pixley, Panini UK Ltd.
• Doctor Who Magazine Special Edition #8, 1st September 2004, “Take It To The Limit” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #25, 2018, “Story 86: The Masque Of Mandragora”, edited by Mark Wright, Hachette Partworks Ltd.
• Doctor Who: The Handbook: The Fourth Doctor by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing.
• Doctor Who: The Seventies by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing.
• In·Vision #15, April 1989, “Production” edited by Justin Richards and Peter Anghelides, Cybermark Services.