'Lux' (Story Code 15.02) by Russell T Davies

“The question is: who chains up a cinema? Those chains are strong. Like they’re locking up a wild beast.” - The Doctor

“Don’t make me laugh!” - Mr Ring-a-Ding

At the Palazzo Picture House in Miami, Florida in 1952, a small audience of movie-goers watches a newsreel about atomic bomb tests. In the projection room, the projectionist, Mr Pye lines up and starts a new reel of film, ‘Mr Ring-a-Ding Goes to Town’, starring a funny singing cartoon character who lives in Sunny Town with his friend Sunshine Sally. But when moonlight shines from a window onto the film, Mr Ring-a-Ding suddenly comes to life. After talking directly to the audience, Mr Ring-a-Ding then steps out of the screen and into the cinema, and the audience starts screaming…

In the TARDIS, the Doctor’s attempts to take Belinda home are still being thwarted, as something bounces the ship off 24th May 2025. The Doctor jury-rigs a new device, a Vortex Indicator, which he hopes will allow them to reel themselves in on the unreachable day. The TARDIS arrives in 1952 Miami, so the two time-travellers grab a change of clothes and nip outside for a quick look around. The night streets are empty, allowing the Doctor to get a reading from his ‘Vindicator’. The Doctor’s interest is then piqued by the nearby Palazzo Picture House, its doors chained up despite advertising a showing of ‘The Harvest Bringer’ starring Rock Hudson, and flowers left for missing people. Belinda wants to go home, but the Doctor insists they investigate the mystery. The two friends visit a nearby diner, where they learn that fifteen people mysteriously disappeared from the cinema three months ago. The café owner bends the segregation laws to allow the Doctor and Belinda to speak to Mrs Lowenstein, whose son was one of those who vanished. After the Doctor promises to find the missing boy, he and Belinda discover that the only person inside the cinema is Mr Pye: the projectionist is now acting as caretaker, and is still playing movies to an empty house. When Belinda finally gives in to the Doctor’s desire to investigate the mystery, the Time Lord sonics the chains securing the doors. Inside, the Doctor and Belinda look for Mr Pye, but are astonished to instead meet Mr Ring-a-Ding: the sinister, diminutive cartoon is very much alive, and even has his own soundtrack. When the Doctor picks up on Mr Ring-a-Ding’s catchphrase of ‘don’t make me laugh’, the cartoon laughs a familiar Giggle - and outside, some of the theatre sign’s letters fall to reveal a new title: ‘HARBINGER’. Mr Ring-a-Ding has been taken over by Lux Imperator, the God of Light, one of the Pantheon gods of chaos - and he knows that the Doctor has defeated others of his kind. Seeing the Doctor and Belinda under threat, Mr Pye plays Mr Ring-a-Ding’s cartoon, forcing Lux to sing along with himself, and allowing the time-travellers to reach the safety of the projection room. However, Mr Pye refuses to leave the building, explaining that Mr Ring-a-Ding has used a home movie to bring his late wife back to life. Belinda spots a strip of film hanging nearby, containing images of the missing people trapped in its frames. Slipping under the door, the two-dimensional Mr Ring-a-Ding threatens to burn the film of Mrs Pye; but he is distracted by the Doctor, whose citing of the rules that bind the gods forces the creature into explaining how moonlight brought him to life. The Doctor also tries to find out how to defeat Mr Ring-a-Ding, but the answer of ‘what have I not done?’ is a riddle he cannot yet solve. Taking over the two projectors, Mr Ring-a-Ding shines their lights onto the Doctor and Belinda, trapping them as 2-D characters in a cartoon world. When Belinda becomes sad, she literally becomes more well-rounded, so the Doctor reveals the truth about being the last Time Lord, enabling him to become 3-D again too. Restored to normal, the duo then deliberately scroll the film they are trapped within, enabling them to return to the cinema. Here they are confronted by Mrs Lowenstein, who has called a cop; the policeman holds the Doctor and Belinda at gunpoint, charging them for their presence in a segregated cinema. But the Doctor sees through them, knowing that they are not real - he and Belinda are still trapped in the film. The Doctor and Belinda next try pushing at the screen in front of them - allowing them to emerge from a television set in the living room of three ‘Doctor Who’ fans! Over a cup of tea, the Doctor learns from a very excited Lizzie, Hassan and Robyn that he and Belinda are fictional characters in a popular television show (to the Doctor’s annoyance, their favourite episode is ‘Blink’, and they think his current story is a bit of a let-down). After Robyn notes Mr Ring-a-Ding’s talk of burning film stock, but is unable to say more, the Doctor realises that it is the fans who are not real - he and Belinda are still trapped in the film. The three brave fans send their heroes back into the television set, despite knowing that this will mean the end of their own existence. Finding themselves back in the white void of the filmstrip, the Doctor and Belinda grab the frame and stop the movie; this causes the projector to overheat, burning the film and returning the duo to the Palazzo theatre. Belinda is concerned that the Doctor has burnt his hand in their escape, but he causally uses some residual bi-generation energy to heal himself. Mr Ring-a-Ding reappears and seizes the Doctor with animated filmstrips from the projectors. Pulled up the stairs and suspended against a wall by the film reels, the Doctor is powerless as Mr Ring-a-Ding begins to drain his Time Lord energy. This stolen light causes Mr Ring-a-Ding to become real, his body becoming three dimensional and growing in stature, which will enable him to leave the theatre and wreak chaos on the world. Seeing that it is daylight outside, Belinda empties all the film cans in the cinema’s vault and then races to the projection room to get matches from Mr Pye. Meanwhile, the projectionist sees his wife again, as she hands him a box of matches and tells him to find her. Ordering Belinda to get to safety, Mr Pye sets light to the mass of spilled film, which promptly explodes. The blast frees the Doctor, and smashes a hole in the theatre’s walls. As sunlight shines inside and onto Mr Ring-a-Ding, the god of light grows even bigger: he outgrows the cinema, and continues out into space, his body eventually dissipating into infinity, becoming light without end… The threat ended, the Doctor reopens the cinema, just as the missing audience members returns. The Doctor and Belinda leave in the TARDIS, unaware that somehow, Mrs Flood is there to watch them depart…

In their living room, Lizzie, Hassan and Robyn are elated to discover they are still alive…

Ncuti Gatwa (The Doctor), Varada Sethu (Belinda Chandra), Ian Shaw (Newsreader), Cassius Hackforth (Tommy Lee), Ryan Speakman (Husband), Linus Roache (Reginald Pye), Alan Cumming (Mr Ring-a-Ding), Millie O’Connell (Sunshine Sally), Lewis Cornay (Logan Cheever), Lucy Thackeray (Renée Lowenstein), Jane Hancock (Helen Pye), William Meredith (Policeman), Samir Arrian (Hassan Chowdry), Bronté Barbé (Lizzie Abel), Steph Lacey (Robyn Gossage), Anita Dobson (Mrs Flood)

Directed by Amanda Brotchie

Produced by Chris May
Executive Producers Russell T Davies, Julie Gardner, Jane Tranter, Joel Collins and Phil Collinson
A Bad Wolf / BBC Wales production

TX (BBC 1 & BBC 1 HD):
19th April 2025 @ 7.15 pm


Notes:
*Featuring the Fifteenth Doctor and Belinda

*This episode premiered in the UK on the BBC's iPlayer in Ultra-High Definition (UHD) on the morning of 19th April 2025, and was simultaneously streamed on Disney+ outside the UK and Ireland

*The end-credits are interrupted by the final sequence with the three ‘Doctor Who’ fans; after this, they resume with the rest of the production team’s credits