When Ace was younger, a derelict mansion in Perivale called Gabriel Chase scared her so badly that she burned it down. The Doctor takes her back to Gabriel Chase in 1883, when it is the home of Josiah Samuel Smith, who is conducting research into evolution against the wishes of the Church. Gabriel Chase hides many secrets: the basement is really a stone spaceship where a creature named Control is imprisoned, an insane big game hunter called Redvers Fenn-Cooper prowls the halls, and Smith himself is rapidly evolving. When Ace releases a powerful entity called Light, the house's dark history will be revealed.

Marc Platt was a longtime fan of Doctor Who, and had been submitting ideas for the programme since 1975. In 1987, he reworked an earlier proposal called “Cat's Cradle” and offered it to script editor Andrew Cartmel. Although Cartmel admired its ideas, he felt that it was too ambitious for the limited Doctor Who budget. Instead, he invited Platt to a meeting, where they were joined by Ben Aaronovitch, who was writing the 1988 season premiere, Remembrance Of The Daleks. After a false start in late 1987 with a period piece called “Shrine”, in 1988 Platt developed a narrative set on Gallifrey entitled “Lungbarrow”. It would see the Doctor facing his greatest fears by confronting his bizarre cousins in their ancestral home of Lungbarrow. It would advance Cartmel's plans to unveil mysterious new details about the Doctor's background by revealing a genetic link with the Other, a shadowy figure from ancient Time Lord history.

Producer John Nathan-Turner, however, was concerned that “Lungbarrow” revealed too much about the Doctor's origins, too quickly. While he liked the setting of a creepy old house and its weird denizens -- inspired by Mervyn Peake's 1946 fantasy novel Titus Groan and its 1950 sequel Gormenghast -- he did not want the Gallifreyan elements retained. Platt agreed to rework his storyline, relocating the mansion house to Victorian England and shifting the focus from the Doctor's greatest fears to Ace's. Some elements of “Lungbarrow” were reimagined for the new setting: Mackenzie, the policeman in suspended animation, had originally been a character trapped in a transporter for three centuries, while Redvers Fenn-Cooper's invitation to Buckingham Palace had been a will for which some of the characters were vying. Cartmel also suggested making evolution a theme of the piece, while Platt's archival work with the BBC Radio Programme Index inspired Light's mission to document all forms of life on Earth.

Marc Platt briefly referred to his storyline as the facetious “Not The Bestiary”

During the autumn of 1988, Platt prepared a revised storyline entitled “The Bestiary”. It was now intended to be the three-part, studio-only story for Season Twenty-Six, and so Platt ensured that it took place entirely within the walls of Gabriel Chase. Although he liked the way “Lungbarrow” had been transformed, Nathan-Turner was unhappy with the title. Platt briefly referred to his storyline as the facetious “Not The Bestiary”, before it became “Life-Cycle” when the scripts were commissioned on November 16th.

Platt drew heavily on Victorian literature as inspiration for “Life-Cycle”. Light was derived from the angels in the works of William Blake; at one stage, Platt hoped that the character could have wings, until Nathan-Turner advised him that this would not be feasible. Control's evolution into a “ladylike” was an accelerated version of Eliza Doolittle's social metamorphosis in the 1913 George Bernard Shaw play Pygmalion. Mrs Grose was lifted from another haunted house story: Henry James' 1898 novel The Turn Of The Screw. Gwendoline was originally called Maud, after the heroine of the 1864 Joseph Sheridan Le Fanu novel Uncle Silas; the name was changed when it was learned that a BBC adaptation of the book -- as The Dark Angel -- would likely air around the same time. Gwendoline was the name of Platt's mother; similarly, his father was called Ernest and Josiah was one of his grandfathers. Redvers Fenn-Cooper was based on H Rider Haggard's classic adventurer Allan Quatermain, who debuted in King Solomon's Mines (1885). The character's name was an homage to James Fenimore Cooper, author of the 1826 novel The Last Of The Mohicans. Nimrod, meanwhile, came from the renowned hunter and great-grandson of Noah, as mentioned in the Bible.

As “Life-Cycle” developed, Nathan-Turner became concerned about the lack of a traditional Doctor Who monster. In response, Platt devised the husks in the basement, which represented Josiah Samuel Smith's earlier evolutionary forms. Originally, he envisaged an army of the creatures, before the numbers were trimmed to three and then just two, omitting a fish-man husk. It was hoped that the faces of the reptilian and insectoid husks might incorporate echoes of Josiah's human features. At a late stage, Platt considered changing Josiah's middle name to Solomon, to avoid any potential issues with the Samuel Smith Brewery company from whom he had borrowed the name in the first place.

In April 1989, the adventure's title became Ghost Light. It was planned to be the third story of Season Twenty-Six but, in June, it was interchanged with the intended second story, The Curse Of Fenric, because Nathan-Turner wanted the latter to air around Hallowe'en. Unfortunately, this undermined a premonition of Ghost Light which had been incorporated into The Curse Of Fenric. Here, Ace alluded to an evil old house in Perivale, the implication being that the Doctor subsequently decided to bring her there to face whatever had scared her. Ghost Light would be made by director Alan Wareing in tandem with the season finale, Survival.

Wareing's first order of business for Ghost Light was to record establishing shots of Gabriel Chase at Stanton Court in Weymouth, Dorset on June 21st. The remainder of the serial was then taped at BBC Television Centre Studio 3 in White City, London. Some of the studio work was attended by EastEnders assistant script editor Colin Brake, who was being considered as a possible successor to Cartmel should Doctor Who continue to a twenty-seventh season in 1990; other candidates included Aaronovitch and Platt. Brake would later write several Doctor Who novels and audio plays, beginning with Escape Velocity from BBC Books in 2001. Meanwhile, the BBC had now resolved an industrial dispute involving one of its unions, the Broadcasting and Entertainment Trades Alliance, which had impacted production on both Battlefield and Survival.

The first studio block took place on July 18th and 19th, with the main focus being material in the trophy room and the observatories. Some scenes in the access tunnel, the lift and the study were also taped on the second day, but Wareing fell badly behind schedule. As a result, several sequences in the study were either dropped altogether -- such as Nimrod tendering his resignation -- or relocated to other sets. Amongst the latter was Mackenzie being chased by a machete-wielding night maid, which was moved to the hallway only to be dropped in editing, thus losing the explanation for his hurry during his fateful encounter with Light.

The final studio session for Season Twenty-Six ran from August 1st to 3rd. Of principal concern throughout was action in the hallways, the drawing room, the dining room, and the empty bedroom where Fenn-Cooper was held. More lift scenes were recorded on the first two days, and those in Gwendoline's bedroom on the last day. When the Doctor and Ace met Reverend Matthews, the Doctor was meant to pound out an anachronistic boogie-woogie piece on the piano before switching to Ludwig von Beethoven's 1801 composition Piano Sonata No 14, better known as the Moonlight Sonata. However, Sylvester McCoy was unhappy with the quality of his mimed playing, and the joke was dropped. It was McCoy's idea to change the Doctor's closing line from “That's my girl!” to “Wicked.”

It became clear that Season 27 would, at the very least, face a lengthy postponement

By the time production ended on Doctor Who's twenty-sixth season, rumours were already rampant that the programme was about to be cancelled. Matters were by no means improved when the new run of episodes premiered on September 6th with Battlefield Episode One, which earned historically low viewing figures. It quickly became clear that Season Twenty-Seven would, at the very least, face a lengthy postponement.

As such, on September 11th, Nathan-Turner had the unenviable task of informing McCoy and Sophie Aldred that their contract options were not being taken up. Ghost Light would mark the last Doctor Who credits for Cartmel and Wareing, and it was Platt's only script for the series; however, he would receive acknowledgment for helping to inspire 2006's Rise Of The Cybermen / The Age Of Steel. As Doctor Who celebrated its twenty-sixth anniversary on November 23rd, Peter Cregeen, the BBC's Head of Series and Serials, confirmed in the pages of the Radio Times that fans could expect a longer-than-usual wait before Season Twenty-Seven entered production -- although he vowed that Doctor Who had not been cancelled.

McCoy now assumed that his time as the Seventh Doctor had come to an end. Nathan-Turner was adamant that he had produced his final episode of Doctor Who for television -- and, indeed, he left the BBC on August 31st, 1990 to become a freelancer. The Doctor Who production office was formally closed with his departure. As it turned out, however, both men were very much mistaken...

• Doctor Who Magazine #190, 2nd September 1992, “Archive: Ghost Light” by Andrew Pixley, Marvel Comics UK Ltd.
• Doctor Who Magazine Special Edition #10, 13th April 2005, “Ride On Time” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #46, 2018, “Story 153: Ghost Light”, 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 #102, May 2002, “Production” edited by Anthony Brown, Cybermark Services.