Lost Property (audio story)

 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.

Publisher's summary
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 meets a man with a very familiar face – and a terrible warning.

Cast

 * 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

Continuity

 * 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, et al.)
 * 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, et al.)
 * 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 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, et al.) and an "expert in oncoming storms". (PROSE: Love and War, et al.)
 * The Eighth Doctor is deeply afraid of being forever stranded on Earth. (PROSE: The Burning, AUDIO: Orbis, et al.)
 * 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, et al.)