'Doctor Who': Could A Musical Easter Egg In 'Lux' Hint At What's To Come?

WARNING! SPOILERS for Doctor Who 1x502/2x02, 'Lux'.

Following the appearance of The Toymaker in 'The Giggle' and Maestro in 'The Devil's Chord', 'Lux', the second episode of Doctor Who's latest season, continues a recurring subplot by pitting The Fifteenth Doctor and new companion Belinda Chandra against a third member of the Pantheon, Lux Imperator, a God of light appearing in the form of living cartoon Mr. Ring-a-Ding.

Keen-eared fans noticed that the episode features an Easter Egg in the form of a reused piece of Murray Gold's score from past seasons, with some now theorising that the inclusion of the music could foreshadow what's to come as the series continues.

A Musical Clue?

Lux Imperator's biggest move in the episode is trapping The Doctor and Belinda inside a film reel, a fate that had already befallen fifteen civilian movie-goers in the Cinema where the light god had emerged. After failing to escape by rolling themselves to the end of the reel, The Doctor and Belinda appear to break out of their confinement via smashing the Fourth Wall, where they encounter Hassan, Lizzie, and Robyn, a trio of seemingly real-life Whovians who had been watching the show.

After a rather sweet sequence in which The Doctor and Belinda befriend the fans, and discuss their favourite episodes, a bittersweet bomb is dropped.. With their deep knowledge of Doctor Who episodes and lore, Lizzie, Hassan and Robyn, have developed the self-awareness to realise that they are not real, and just another part of the Lux/Ring-a-Ding's trap. The three urge The Doctor and Belinda to escape, even though it means they will fade from existence. When they hesitate, Lizzie closes the frame herself to free them.

The sequence during which the Whovians make their realisation is accompanied by 'The Sad Man with a Box', a track that composer Murray Gold originally wrote for series five of Doctor Who, the first to star Matt Smith as The Eleventh Doctor. It most prominently plays in the series five finale, 'The Big Bang', during the scene in which The Doctor, fading from memory, tells his story to a sleeping Amelia Pond.

If Something Can Be Remembered, It Can Come Back

When he is captured again by Lux after escaping the film, The Doctor reminds Belinda of the Whovians, encouraging her to use their memory as inspiration to go on. A brief clip during the episode's closing credits reveals that, somehow, Lizzie, Hassan, and Robyn have survived.

Some fans believe that the use of 'Sad Man with a Box' foreshadowed this outcome, and that the trio exist again precisely because Belinda and The Doctor remembered them, similarly to how Amy Pond was able to remember The Eleventh Doctor back into existence after his temporary erasure in 'The Big Bang'.

A hint at the future?

Considering all the above, a larger theory has formed, proposing that the callback to series five may be a hint at what's to come for the remainder of series fifteen/season two. The mysterious Mrs. Flood, assumed to be a villain at this point, could be someone The Doctor has forgotten, or who believes that The Doctor has forgotten them.

Alternatively, there could be something that The Doctor, or perhaps Belinda will have to remember to defeat the looming threat to planet Earth that is currently preventing The Doctor from returning Belinda on the date of her departure.

Perhaps Whovians should keep an ear out for significant score-related clues as the series continues.