- Acting for Two: Everyone who has a robot duplicate.
- Creator Backlash:
By the time I got to the last story, I was very sad. Nick had gone, Pertwee had gone, Katy had gone, Roger was dead, and there I was, lonely Sergeant Benton. I found that a very hard story - sad, lonely and difficult.
- Terry Nation felt the story was a nice idea with an intriguing mystery, but didn't feel the end product quite fulfilled his vision.
- John Levene found making the story an unhappy experience:
I didn't care for "The Android Invasion" one bit. There was no reason for Harry to be in it at all - I couldn't see the point of it. My last scene was particuarly frustrating, as Harry just sort of fizzled out, tied up on the floor in the corner of the room. I don't mean that as any disrespect to Patrick Newell, who made me laugh a lot and was wonderful to be with, or to Martin Friend who is an old mate anyway. They both did their best to cheer me up. My own unfulfilled wish was that Harry could have been blown up while trying to save Sarah Jane, or something on those lines a genuinely heroic exit instead of what I actually got.
- Ian Marter was also unhappy with his lot:
- Deleted Scene:
- The first scene of main guest lead Guy Crayford was removed in post. It was also the first scene of Chief Technician Grierson. Dave Carter is still credited for part one despite his only scene being cut.
- Timing reasons meant that a key scene which would have explained how the Doctor reactivated his android duplicate, as well as accounting for the Kraal invasion armada was cut.
- Dyeing for Your Art: Yes, Tom Baker himself dived into the pond. His voice doesn't sound right later on because he'd fallen ill from the water.
- Not to mention he was terrified of water.
- Spared by the Cut: Ian Marter would have preferred it if Harry had died saving Sarah.
- Throw It In!: Tom Baker and Elisabeth Sladen notoriously rewrote and ad-libbed most of their material due to hating the script, including the entire ending scene. Some are obvious unrehearsed adlibs, which have a noticeably more natural, mumbly feel than Doctor Who acting usually does (like the Doctor and Sarah's "fee fi fo fum" bit). The original dialogue was at best functional the rewritten dialogue is much odder and more exciting as well as showing off how well-read Baker actually was when making off-the-cuff references to Anna Karenina and namedropping obscure historical figures.
- What Could Have Been:
- The Brigadier was supposed to be in this story, but Nicholas Courtney had a theatrical commitment. Thus, his lines were given to Colonel Farraday.
- Originally, a key plot element was that the Kraal androids were in fact mirror images of the people they were imitating, and this was how the Doctor deduced that Sarah Jane was actually a robot. It was eventually decided that this would be too technically demanding to realise, and the action was suitably amended.
- Terry Nation envisaged the Kraals as somewhat insectoid in appearance, although this idea was not used in the design work.
- Working Title: The Kraals, The Kraal Invasion, and The Enemy Within.
- You Look Familiar: Milton Johns (Guy Crayford) had appeared as Benik in "The Enemy of the World".
- You Sound Familiar: Dalek voice actor Roy Skelton voices Chedaki using his Zippy voice.
Trivia / Doctor Who S13 E4 "The Android Invasion"