Spoilers are precisely defined here. Rules vary by the story's medium. Info from television stories can't be added here until after the top or bottom of the hour, British time, closest to the end credits roll on BBC One. Therefore, fans in the Americas who are sensitive to spoilers should avoid Tardis on Sundays until they've seen the episode.



The Darkness of Glass was the second story in the fourth series of the Fourth Doctor Adventures, produced by Big Finish Productions. It was written by Justin Richards and featured Tom Baker as the Fourth Doctor and Louise Jameson as Leela.

Publisher's summary[]

Cut off from the TARDIS, the Doctor and Leela find themselves stranded on a small island. But they are not alone. It is 1907, and members of the Caversham Society have gathered on the hundredth anniversary of the death of Mannering Caversham, the greatest Magic Lanternist who ever lived.

But Caversham was also a supernaturalist who claimed to have conjured up a demon from the depths of hell. As people start to die, the Doctor begins to wonder if Caversham's story might have more than a grain of truth in it. Can the Doctor and Leela discover what really happened to Caversham a century ago? And if they do, will they live to tell the tale..?


Part one[]

The Doctor and Leela arrive on an English island and the Doctor decides they will explore a little bit since the TARDIS has to do some calibrating. Along one of the paths, they feel the tide coming in and with the way to the TARDIS washed over, they decide to take refuge in a castle they spot nearby. There they meet Professor Oliver Mortlake, Joseph Holman, Mrs. Porter and Mary Summersby who explain to them the purpose of their being present in the castle. Joseph is a lanternist and explains to them the purpose of lanterning and the 100 year celebration in the castle on the anniversary of the death of Mannering Caversham, a legendary lanternist who died by suicide after supposedly summoning a demon. Just then they all hear a cry and go investigate, only to find a man dead.

The Doctor has the body stored in the basement while he and Leela investigate. They find a glass window with a missing piece and they reckon the demon is a beast on the loose. Leela and the Doctor split up to investigate further.

They both begin to notice interesting features of the castle, specifically pieces of perfectly square-cut glass missing from windows around the castle. As Leela takes Professor Mortlake and David Lacey around the castle to try to find the demon that Leela suspects is the culprit of the murders, they stumble upon a wall engulfed in shadow and Leela realises it is the demon as it kills another victim....

Part two[]

Leela helps Professor Mortlake escape the demon and they go to barricade themselves in a room with Mr. Holman and David Lacey. Holman is persuaded by Professor Mortlake to perform his magic lantern show for them in the meantime while they wait for the Doctor. Meanwhile, Mary helps the Doctor investigate the castle archives and finds the plans for the castle, where they discover that the glass pane in the great hall was not all black as it is now and they reckon it was used to trap the shadow demon by Mannering Caversham who they hypothesise had opened a realm and accidentally released the demon, so he tried to seal it by sealing it into different panes of glass, and spreading it around the castle. They further reckon that someone is stealing the pieces and is trying to release the demon by reassmebling the pieces. Mary points out that the perfect squares of glass are the same size as the glass used in Holman's glass slides, but after some thinking and accusations, the Doctor realises it couldn't be Holman or Mary attempting to summon it. They run off to find Leela and split up on the Doctor's orders where he tells Mary to prepare some mirrors.

Holman's slide show begins to project the demon which startles Leela and the others but the Doctor arrives and reveals it was Professor Mortlake who is the culprit. His charade revealed, he pulls out a gun and demands the summoning be finished. The Doctor, however, using Mannering Caversham's original method, manages to re-seal the demon in the glass with help from Mary and Leela, the latter whom ends up having Professor Mortlake fall out the window to his supposed death.

In the aftermath, Mary, Mr. Holman and David thank the Doctor and Leela while the Doctor collects some fragments of the shattered glass with parts of the demon still sealed inside in a biscuit tin and says he and Leela will find some place very far away to dispose of the glass so that the demon can never be re-summoned. Mary offers the two a place to stay for a while but they politely decline and depart saying they must return to their dog who is waiting for them in the TARDIS.


Uncredited Cast[]



Textless cover.

  • The idea for this story came from a line in the T.S. Eliot poem "The Love Song of J. Alfred Prufrock": "...as if a magic lantern threw the nerves in patterns on a screen". The original title was A Pattern of Nerves. (VOR 72)
  • This story was originally released on CD and download.
  • The Doctor says "QED is for 'he is wrong' ". QED is actually Latin and stands for 'quod erat demonstrandum', or "that which has been demonstrated". It is often used in mathematics and logic to signify the end of a proof. The Doctor says after showing Leela evidence why Mortlake's claim was wrong.
  • This story was recorded on 21 March 2013 at Audio Sorcery.


External links[]