History Recap / DoctorWhoS9E4TheMutants

* BaldOfAwesome: Sondergaard, especially if, as seems likely, his baldness is due to radiation exposure.

* {{Antimatter}}: The Doctor claims that an antimatter explosion will turn everyone into "un-people un-doing un-things un-together," which is an awfully convoluted way of saying "dead."

* {{Unishment}}: When the Doctor discovers what the crystal that he and Sondergaard discovered in the thaesium mines actually is (a lens/radiation converter, which the Solonians need to complete their metamorphosis), The Marshal and his officers burst in on Jaeger's laboratory to imprison Sondergaard and Jo in the thaesium refueling lock along with Ky, to kill them by radiation poisoning. The one thing The Marshal doesn't know is that Jo has the crystal, and the crystal needs thaesium to work...

* Unishment: When the Doctor discovers what the crystal that he and Sondergaard discovered in the thaesium mines actually is (a lens/radiation converter, which the Solonians need to complete their metamorphosis), The Marshal and his officers burst in on Jaeger's laboratory to imprison Sondergaard and Jo in the thaesium refueling lock along with Ky, to kill them by radiation poisoning. The one thing The Marshal doesn't know is that Jo has the crystal, and the crystal needs thaesium to work...

* ColorblindCasting: Cotton was originally written as a Cockney, but director Christopher Barry cast the Caribbean-born Rick James - without re-writing the character's speech patterns.

* ColorblindCasting: Cotten was originally written as a Cockney, but director Christopher Barry cast the Caribbean-born Rick James - without re-writing the character's speech patterns.

* ColorblindCasting: Cotton was originally a Cockney, but Christopher Barry decided to cast a black actor in the role. Without altering his speech patterns.

* HostileTerraforming: The episode has a group of evil human colonists plotting to terraform an inhabited planet in a way that will genocide the indigenous sentient culture.

* HeelFaceTurn: Stubbs and Cotton after realising how evil the Marshal is. By the end of the story

* {{Mutants}} - Naturally!
** But averted: It's not a mutation but a metamorphosis.

* RewardedAsATraitorDeserves: Varan's Son assassinates Ky on behalf on the Marshal. When he comes to the Marshal's office to collect the promised reward, the Marshal shoots him with a dart gun.

* ThoseTwoGuys[=/=]ThoseTwoBadGuys: Stubbs and Cotton, the two security guards who chip in with observations throughout the story.

* FatBastard: the Marshal

* GreenRocks: "Particle reversal", used to explain just about every SF element in the plot.

The one with Buddhism.

* ThickerThanWater: Varan choses his own son for the assassin, which he cites as proof of his absolute reliability.

* AllThereInTheManual: In the novelisation, the Doctor describes the use of message pods as a system used for a "real emergency" and that the "Time Lords' code" compels him to deliver it.
** In addition to the stone tablets seen onscreen, the message pod also contains parchment scrolls.
** Jaeger is given some backstory as being disgraced on Earth for stealing data from an academic colleague.
** Varan's son is given a name, Vorn.
** There is a secret passage underneath the Marshal's desk.
** The Marshal is given back story as having come to Skybase as a security guard and worked his way up the ranks, meaning he has no connections on Earth.

* EveryoneCallsHimBarkeep - they really go for it in this story, with the Marshall, the Administrator and the Investigator. It's not just the humans - Varan's son doesn't get a name either (although he is given one - Vorn - in the [[Literature/DoctorWhoNovelisations novelisation]]).

* ObscuredSpecialEeffects: Ky's transformation from a HumanAlien to an insect-like monster was done with a StopTrick and fade with an extreme closeup of his hand only, saving full-body makeup.

* OneGenderRace - no female Solonians are visible at any point. Then again, this is one of the few ''Series/DoctorWho'' stories with no female guest cast members at all.

* PowerGlows: the cave, the radiation chamber and the final mutation of the Solonians all glow.
* {{Planetville}}

* {{Revenge}}

* ThoseTwoGuys/ ThoseTwoBadGuys - Stubbs and Cotton, the two security guards who chip in with observations throughout the story.

* FantasticSlurs: "mutt" (originally intended to be "munt", a real ethnic slur used by English-speaking people in southern Africa against black Africans)

* BizarreAlienBiology: The truth behind the Solos natives' mutations: [[spoiler: they're undergoing a natural metamorphosis that'll allow them to survive their world's cyclical climactic shifts, which was triggered early due to the Marshal's terraforming efforts.]]

--> The Doctor: "Marshal, you are quite mad".
--> The Marshal: "Only when I lose".