Two themes seem to be developing this season on Doctor Who, the prospect of death and the consequence of changing the past. There was a hint of both in the first two-part story involving the Daleks and Davros, and the prospect of the Doctor killing Davros as a young boy and stop the development of the Daleks. By showing mercy, he winds up giving the Daleks a pesky mutation called mercy.

In “Before the Flood”, the Doctor again goes into the past to change the present, and save Clara and the underwater mining crew from some menacing ghosts. This time, though, he is told that his ghost has shown up outside the facility. He thinks this shows he will die, and he’s afraid to change the future even to save himself. For much of the series, the Doctor has been very reluctant to change the past.

Before all that, he does something he hasn’t done in nearly 50 years…he talks to us, the viewers.
He tells a story about a time traveler who wants to meet Beethoven, but no one has heard of him. So, the time traveler takes the copies of Beethoven’s music he happens to have and gets them published. The man becomes Beethoven, and the timeline is preserved. Sounds like an episode of Peabody’s Improbable History, but the Doctor says that never happened. His story is an example of the bootstrap paradox, where a future event is caused by a past event through time travel. Through that method, the Daleks got something they didn’t want, mercy. However, can he use that again to save himself?

He’s gone to 1980 to that military area in Scotland to see what happened to that spaceship when it first arrived before that valley was flooded. O’Donnell (Morvel Christie) and Bennett (Arsher Ali), part of the mining crew, are with him. They meet Prentis (Paul Kaye), who was the first ghost. He’s a mortician from the planet Tivoli, and he drove the ship to bury the Fisher King (Neil Fingleton), who dominated his planet for ten years before someone else took over. By custom, he’s supposed to be buried on Earth because it’s a barren place.

When the Doctor is told about his “ghost,” he says he has to die because he can’t change the future.  Clara won’t hear of it, insisting that he find a way. He’s also told the ghost is saying, silently, the names of the crew, Clara and the Doctor. It also frees the ghosts from the Faraday Cage, and says “the chamber will open tonight”.

The Fisher King soon kills Prentis and O’Donnell, which means their ghosts show up in the future. Clara, meanwhile, suggests crew member Lunn (Zaqi Ismail) try to get the phone because he didn’t see the words that were inside the alien ship. This upsets Cass (Sophie Leigh Stone), the leader. Through sign language, she also asks Clara if traveling with the Doctor has changed her, or she enjoys endangering others. Clara says she just does what has to be done. It shows that Clara is more like the Doctor than she thinks.

The Doctor soon learns he can’t avoid his confrontation with the Fisher King because the TARDIS has trapped him in his timeline. He actually sees himself at the start of the episode talking to O’Donnell, almost like a scene from Primer.  The creature says he wants to create more ghosts and use them to contact his people. That will eventually lead to the conquest of Earth, and it is confident the Doctor can’t stop it if he won’t change his history.

However, the  Doctor admits a ghastly future is better than none at all, which may be what he remembered when he decided to let Davros live despite his destiny. Also, the Fisher King also bent the rules of life and death by turning souls into transmitters. He tells the creature he’s removed the words from the ship, but he didn’t. It’s part of a plot to flood the valley and drown the creature. The Doctor is protected by the suspended animation chamber, which opens in front of Cass, Dunn and Clara in 2119. The ghosts wind up trapped in the Faraday Cage.

The final explanation for everything seems a bit too neat.  The Ghost Doctor was a programmed hologram, the sonic sunglasses erased the memory of the alien words from the remaining crew, and the ghosts will eventually be taken away. Bennett, though, wonders what to do after losing O’Donnell. Clara, who knows how he feels because she lost Danny Pink, tells him to keep going because there’s a galaxy out there to experience. This convinces him to help Lunn and Cass finally get together. Seeing Cass’ expression, and then her kissing Lunn, is a sweet moment to end things.

Still, how did the Doctor know to make that ghost hologram, then be convinced by it to confront the Fisher King? Was it because he got involved in the events by going back in time?
If so, it would fit how the first story ended, with the future being changed by the past through time travel. Instead of resigning himself to his fate, he decided to pull himself up by his “bootstrap paradox,” which explains why he gave us that story to start the episode. That may show his new attitude towards tweaking the future. After all, it had happened in “Fires of Pompeii” when he was convinced to save a few more people than history recorded.

Also, the show  got a new theme song arrangement with a mean electric guitar.

A bigger mystery will be revealed next week: what’s Maisie Williams doing on the show? Vikings seem to be involved.