It's still Manhattan. There are still Daleks. They attempt to create a race of Daleks in human bodies, using the Empire State Building as a lightning rod. Dalek Sec is now part human, which the other Daleks really
don't like, and he wants to build their Daleks-in-human-bodies army to be part human as well, which the other Daleks like even less.
The Doctor, however, notices that Dalek Sec is developing human emotions, and races to help him, because sometimes one person with the right idea in the right place is all it takes to change the world. At the same time, Martha and Tallulah try to find what alterations the Daleks made to the Empire State Building.
Things get too touchy-feely for the other Daleks, who capture Dalek Sec and go back to the original plan of full-Daleks in human bodies. The newly piggyfied Lazlo helps the Doctor escape, and after wasting time
hugging Martha, sets off to remove the Dalekenium
from the lightning rod.
As Martha improvises a death trap for the Dalek pig slaves, the Doctor fails to remove the Dalekenium, so he throws himself in the way of the lightning and, in what will be a continuing theme throughout this series, screams in absolute agony. The radiation revives the Daleks' army, but the resulting Daleks in human bodies become Time Lord/Dalek hybrids in human bodies instead. The Doctor is delighted at having created a new species.
Dalek Sec sacrifices himself to save the Doctor; the new hybrid species refuses to shoot him, attacking the Daleks instead, and two of the remaining pure Daleks die in the process. Dalek Caan kills off the rest of the hybrids (to the Doctor's dismay), refuses the Doctor's offer of help and escapes. Laszlo is kept alive by the Doctor using the Daleks' genetics lab, although he'll be half-pig forever. Talullah doesn't mind too much.
- Absurdly Spacious Sewer
- AcCENT Upon the Wrong SylLABle: An unusual case with Dalek Sec, as he speaks in a breathy near-whisper, but still utilizes the Dalek inflection.
- Assimilation Backfire: Hybrid-Sec finds himself developing human values and emotions as a result of absorbing human DNA, which eventually causes the other Daleks to execute him in disgust.
- Big Applesauce: Tallulah says "if aliens had to come to Earth, no wonder they came here" while looking breathlessly at the Manhattan skyline. Of course, the funny thing is that many, many more have targeted London and Cardiff.
- Black Dude Dies First: Invoked and enforced — Daleks have been taking humans for experimentation and conversion into either pig slaves or human Daleks, up until Solomon tried to reason with them.
- Bond Villain Stupidity: The Doctor standing on the backs of the theater seats, staring straight at the Daleks who are inexplicably not shooting him despite the fact that he more or less asked them to, could be the poster image for this Trope.
- Captain Obvious: "They killed them, rather than let them live."
- Close-Knit Community: The Hooverville
- Continuity Nod: Although they don't use the terms "the Dalek/Human Factor", the plot concept of the Daleks wanting to imbue humans with the Dalek nature and the Doctor wanting to imbue Daleks with the human nature is very reminiscent of "The Evil of the Daleks".
- Dalekpunk: Amusingly, the hybrid army is armed with Dalek tommyguns.
- Disney Death: The Doctor.
- Driven to Suicide / Get It Over With / Suicide by Cop: The Doctor right after Solomon's death. He actually dares the Dalek that just killed Solomon to go ahead and kill him next... and there's absolutely nothing in the story or Tennant's performance to indicate that he's bluffing or has some kind of brilliant plan up his sleeve. It seems that watching a good man the Doctor had grown to like and respect get killed right after appealing to a better nature Daleks just don't have was the very last straw. Daleks just seem to bring out all the Doctor's darker emotions, even the ones that cloud his desire for self-preservation.
- Foreshadowing: Less pertaining to the episode specifically and more to the series as a whole, "I am Dalek Sec, and you will obey me!"
- Gossipy Hens: Thay and Caan discuss their doubts about Sec's new orders. Caan even checks to make sure no-one can hear them.
- Half-Human Hybrid
- Heel-Face Turn: After becoming a Half-Human Hybrid, Dalek Sec changes his plans for Earth, and instead opts to recreate the Daleks all as half-humans instead of full Daleks in human form. He convinces the Doctor to prepare for the gamma storm that will give the new race life and pleads for use of his TARDIS to take them to a planet so they can begin anew. Sadly It doesn't work as Dalek Caan and the other two betray him at the last minute, switch the transformation to full Dalek and capture and kill Sec.
- Heroic Sacrifice: From Dalek Sec, of all people — when Thay fires at the Doctor, Sec (who has been crawling on all fours like a dog) gets up and is hit by the shot instead.
- Humanity Is Infectious: Dalek Sec eventually rejects the Dalek's warmongering, and tells the rest of the Cultists if they continue their Dalek ways, they'll find nothing but destruction.
- Humans Are the Real Monsters: Cited as Dalek Sec's motivation for combining himself with a human — now he can feel man's hatred, ambition and propensity for war.
- Humans Are Special: The Doctor's counter-argument to Dalek Sec by pointing out the human mind has so much more potential than simply destroying other forms of life. This leads to Humanity Is Infectious, and Dalek Sec eventually changes his plan to make Dalek-Human hybrids and transport them across the universe to rebuild, instead of conquering Earth, which infuriates the other Skaro cultists.
- Ignored Epiphany: Ignored by the other three Daleks, anyway.
- Improvised Lightning Rod: The Doctor uses himself as one for a lightning and cosmic ray strike.
- Landmarking the Hidden Base: A bit of Fridge Brilliance here, as the Empire State Building is the tallest in the world at the time, so it's perfect for attracting radiation from space.
- Lightning Can Do Anything: Gamma lightning, apparently.
- Narm: It's bad enough that Sec has a bunch of what look like penises sticking out of his head, but did they have to constantly be moving?
- Nice Job Fixing It, Villain: Nice Job destroying the last of your race, Dalek Caan.
- Ominous Latin Chanting: During the attack on Hooverville.
- Pig Man
- Plummet Perspective: Subverted. The sonic screwdriver falls far, but not as far as it looks.
- Redemption Equals Death
- Sedgwick Speech: Here's a hint: never try to appeal to a Dalek's compassion.
- Spikes of Villainy: Dalek DNA is shown this way.
- Technicolor Science
- Tragic Villain: Guess.
- Wasteland Elder
- Whoopi Epiphany Speech: Subverted as the aforementioned Sedgwick Speech.
- The X of Y: "X of the Daleks" — First time the classic title format for Dalek episodes shows up in the new series.