"Evolution of the Daleks" completes the Doctor's trip to New York for now, having seen off the Dalek menace, witnessed a Dalek fuse with a human, unwillingly put his faith in this new species and then deliberately become a genetic father to a new hybrid race of human/Dalek/Time Lords, only to watch in horror as they're all killed minutes later.

For him, it's a story of thwarted potential, in that lots of things could have happened, but in the end, it was the same old story of Dalek brutality and human endurance.

Here are a few things that you should keep an eye out for, the next time you watch.

(The episode is available on iTunes and Amazon.)

"Evolution of the Daleks" is the first episode in the new series to use the standard naming convention "... of the Daleks," which, after the First Doctor's era was used for all but one of the Dalek stories in classic Doctor Who. The lone exception (providing you don't count "Death to the Daleks") is the Third Doctor story "Frontier in Space," which features a collaboration between the Daleks and the Master.

One of the scenes that didn't make the final edit saw the Doctor, Martha and Tallulah back in Hooverville, with the Doctor having to admit to Tallulah that he would be unable to change Laszlo back to his old self.

There's a really subtle, and very clever reference to the British sitcom Are You Being Served? that happens when the Doctor arrives in the lift. He jumps out saying, "First Floor, perfumery," in a sing-song voice, much like the first line of the comedy show's theme song. Except the Are You Being Served? theme song follows the British system for naming the floors in a building, ie. the floor at ground level is called the ground floor, so the song begins "Ground floor, perfumery." By saying "first floor," the Doctor is taking a British thing and putting it into an American context, much like this story does.

https://www.youtube.com/watch?v=BaboGNp0crs

Shortly afterwards, this story sees an early outing for the Twelfth Doctor's feelings about public displays of emotion. When the Doctor reunites Laszlo and Tallulah, he pauses to hug Martha, only to see the lift doors shut as he does so. His conclusion? "Never waste time with a hug."

The Doctor has demonstrated an ability to withstand huge electric shocks a few times, most notably in "Terror of the Zygons," "World War Three", "Genesis of the Daleks," and "The Idiot's Lantern." He also described a shocking experience helping Benjamin Franklin in his experiments with a kite in "Smith and Jones."

The Daleks count time in rels, and according to the countdown in this episode, a rel is around 1.2 seconds. The interesting thing is that the rel is one of the few innovations in Doctor Who history to have started in the two 1960s Doctor Who movies (specifially Daleks' Invasion Earth 2150 A.D., starring Peter Cushing as the Doctor) and then made its way into the core TV show.

https://www.youtube.com/watch?v=CUsj3U9WtmA

Martha's throwaway reference to Laszlo and Tallulah being "the pig and the showgirl" is less brutal than it may seem, as it's a play on the title to the 1957 movie The Prince and the Showgirl, starring Marilyn Monroe and Laurence Olivier.

The idea that humans are the "great survivors" is one of Doctor Who's longest-running threads. The earliest reference to mankind's ability to make the best of a bad situation occurs in "The Ark," in which the First Doctor visits Earth's distant future, joining the last of humanity as they leave the planet before it plummets into the Sun. This is a theme picked up again in "Utopia," while the idea of an interstellar warehouse of species pops up in the Fourth Doctor adventure "The Ark in Space," in which humans are once again taking extreme measures in order to survive.

As Dalek Caan operates the temporal shift at the end of the story, the Doctor believes him to be the sole Dalek left and regrets his escape. However, his next incarnation encounters Daleks of far greater vintage (back as far as some of the Doctor's earliest encounters with his greatest foes) in "Asylum of the Daleks," which suggests that even if Caan had been defeated, there would still have been Daleks in the universe. Sorry, Doctor.

https://www.youtube.com/watch?v=f0iV7TUE_rI

Listen to the voices of the individual Daleks as the balance of power shifts from one to another. Nicholas Briggs, voice-over artist to the sons and daughters of Skaro, revealed in a video diary that he made Dalek Caan's voice rise in pitch as he took over command of the Cult of Skaro from Dalek Sec. This was partly done for reasons of comfort—Briggs had given Caan a low, rasping voice in "Doomsday," chiefly because he only had one line—but also for reasons of character development. Daleks clearly respect a shriller voice.

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