- You may be looking for Decalog 2: Lost Property.
Lost Property was the first story in the audio anthology Stranded 1, produced by Big Finish Productions. It was written by Matt Fitton and featured Paul McGann as the Eighth Doctor, Nicola Walker as Liv Chenka, Hattie Morahan as Helen Sinclair and Rebecca Root as Tania Bell, alongside Tom Baker as The Curator.
Trying to find a way to resume his travels, the Doctor calls in some old favours.
As the residents get to know the new arrivals, something else finds its way into Baker Street, seeding suspicion.
Helen parts from Aisha on her way to Baker Street and meets the Curator outside the TARDIS, which now stands as a makeshift library on Camden Road. She tells him that she knows the man who owns it and that he intends on fixing it up. Liv approaches Helen and the Curator, having made about £100 from selling things, and the Curator says goodbye, calling them by their names.
The Doctor is trading parts with Jim, whom he has turned to due to UNIT's defunding. Without the TARDIS, his memory is hazier, but he thinks back to when the TARDIS landed in London having escaped the Crucible of Souls. He, Liv and Helen went to 107 Baker Street, which they found had been partitioned into flats, and met Tania. Jim finds what seems to be a Chinese puzzle box which the Doctor takes, thinking that he could use it to create an interface through which he could jump start the TARDIS.
The Doctor returns to 107 Baker Street where tenants Tania, Ron and Aisha try to get his attention.
The Curator visits Jim and asks what the Doctor took, telling him that time would soon be other than it should. Whilst he believes that the puzzle box is innocuous, he decides to warn the Doctor, Liv and Helen in as subtle a way as he can.
Liv arrives at the house and is let in by Tania. Helen bumps into Ron and hands Aisha back Zakia's Oyster card. The two companions talk to the Doctor about their financial situation and Helen tells Liv that she needs to get a job. The Doctor goes to Midge's shop, where Ron is working part-time, but leaves after learning that Midge is out. He goes into the house's basement believing that there was a homeless person in there, but he finds it empty.
The Curator visits Midge's shop and asks Ron to tell him to go to the Under Gallery.
In a a café, Helen tells Liv that the agency has found tenants for the second floor when the Curator visits, getting a cup of tea and paying their tab. Ken and Robin move in and Robin tells Helen that he saw somebody on the stairs. Robin and Tony have both had things stolen.
A meter reader comes to the house and goes into the basement before running away screaming. Liv and Helen decide to speak to the tenants to investigate and are joined by Tania, who believes that something could be exacerbating the tensions between everyone in the house. Ron and Tony have information that they believe that Helen does not know, but decide not to share it so as not to cause trouble.
In the rain, the Curator meets Robin, who is planning on running away, and gives him money to buy a hot chocolate in the café. As Robin leaves, the Curator says to himself that all things change, but not always for the better.
The Doctor has stolen Robin's game console and is building an interface when he visits Midge, asking him what he had not been told about the puzzle box. Midge tells him that it is one half of the Pandora Bolt, given to him by a future Doctor, and that it should not have been brought within a mile of the other. Midge tells him that he has to drain the Pandora Bolt to stop it.
At the house, Ron and Tony argue with Aisha and Zakia before they unite to shout at Liv and the Doctor. The Doctor descends to the basement and sees a projection of his future self, still trapped on Earth, and links the two parts of the Pandora Bolt to short it out.
Tania calls somebody and tells them that no further action need be taken at the house, the "Level 2 activity" having been resolved. Liv and Helen tell the Doctor to stop keeping to himself, prompting him to return Robin's game console and talk more to the others in the house.
Helen follows the Curator to the Under Gallery to find out who he is, but he says only that he is not Professor River Song. He asks her to look after the Doctor before disappearing, leaving Helen to wonder what calamity is approaching this time.
- The Doctor - Paul McGann
- Liv Chenka - Nicola Walker
- Helen Sinclair - Hattie Morahan
- The Curator - Tom Baker
- Tania Bell - Rebecca Root
- Aisha Akhtar - Amina Zia
- Zakia Akhtar - Avita Jay
- Jim / Midge - Robert Portal
- Meter reader - Raj Ghatak
- Ron Winters - David Shaw-Parker
- Tony Clare - Jeremy Clyde
- Robin Bright-Thompson - Joel James Davison
- Ken Bright-Thompson - Alan Cox
- Aisha works for a temp agency that has her working for the council.
- Aisha tells Helen to take The 27 from Camden Road to Baker Street.
- The TARDIS, now just a police box, is parked on Camden Road.
- The Curator picks up a copy of The Lion, the Witch and the Wardrobe and tells Helen that Jack never liked being called Clive.
- Jim mentions a girl from UNIT who visited him regularly. He describes her as "a bit keen".
- Jim mentions the bootstrap paradox.
- The Curator mentions custard creams.
- Tania mentions Mr Brewster.
- Liv lies to Tania and tells her that her mother took vidsnaps of the house in the 1970s.
- Tania makes Liv an instant hot chocolate.
- Ron goes to Sanjit's shop and buys milk for Tony, who would be annoyed if he did not have any for his morning coffee.
- Helen mentions parking permits, council tax and liability insurance.
- Ron plans on watching a Kenneth More film at six o'clock.
- The Curator says that his "number" is extraordinarily high.
- The Curator asks Mabel for his usual blend with seven sugars.
- The Curator says that the resident of 221B Baker Street has long since retired to the apiaries.
- The Twelfth Doctor left the Pandora Bolt with Midge. When Midge describes this Doctor, the Eighth Doctor initially assumes he is talking about the Third Doctor, but realises it must be a future incarnation.
- Midge is not fond of the shorter Scottish Doctor with the hat.
- Tania calls someone and says that the phenomena at the house was residual Level 2 activity. It had been detected by sensors.
- Ken works in advertising.
- Tania has lived in the house since 2014.
- The Doctor asks Robin if he is playing "another shoot 'em up".
- The Curator feeds pigeons.
- The Doctor is interrogated by a letting agent, who he thinks puts the Daleks to shame,
- This story is notable for introducing the first transgender companion in the Doctor Who universe, Tania Bell.
- The TARDIS has become an empty police box without its interior dimension. (TV: Father's Day)
- Jim's heard rumours that UNIT has been defunded. (TV: Resolution, Spyfall)
- The Doctor thinks about making a sonic screwdriver from the technology available to him in this era. (TV: The Woman Who Fell to Earth)
- The Doctor lends out his Beetle because he can't maintain it himself. (PROSE: Vampire Science, Unnatural History, AUDIO: Eyes of the Master, etc.)
- Helen mentions that she used to work at the National Museum. (AUDIO: The Red Lady)
- Separated from a working TARDIS, the Doctor finds that his memory is failing him. (TV: Spearhead from Space, PROSE: The Burning, etc.)
- The Doctor previously got Jim's help with the Doomsday Chronometer. (AUDIO: The Doomsday Chronometer)
- The TARDIS died after escaping the Crucible of Souls. (AUDIO: Day of the Master)
- Helen left the Doctor's sonic screwdriver on a desert planet. (AUDIO: Planet of Dust)
- The Doctor recalls that he left 107 Baker Street to Thomas Brewster. (AUDIO: A Perfect World)
- Liv remembers Baker Street from 1972. (AUDIO: Eyes of the Master, The World Beyond the Trees)
- The Doctor moves into the attic bedroom. He previously led Molly O'Sullivan here to hide in the priest hole behind the bedroom's mirror. (AUDIO: The White Room)
- The Curator expresses having once had a friendship with a long-retired resident of 221B Baker Street. (PROSE: All-Consuming Fire)
- The Curator was once a hoarder of umbrellas (TV: Time and the Rani, etc.) and an "expert in oncoming storms". (PROSE: Love and War, etc.)
- The Eighth Doctor is deeply afraid of being forever stranded on Earth. (PROSE: The Burning, AUDIO: Orbis, etc.)
- Helen follows the Curator into the Under Gallery. (TV: The Day of the Doctor)
- The Curator assures Helen he is not River Song, although notes she is a "wonderful woman". (AUDIO: The Sonomancer, etc.)
- The Eighth Doctor will once again confuse a description of the Twelfth Doctor with the Third Doctor, this time when described by Josie Day. (COMIC: A Matter of Life and Death)