- Magnificent Bastard: Reegan is a polite, dry-witted career criminal and mercenary hired by General Carrington to implement his plan, who proves to be far smarter and more capable than his employer. Abducting the alien ambassadors, Reegan kills two of his men with their radiation and dumps the bodies with false papers, framing foreign spies for the kidnapping. Luring Liz out with a fake message Reegan kidnaps her and when later ordered to kill the Doctor, Reegan pegs a weak link in conspiracy and tricks him into setting off a bomb hoping to take them both out. Implementing every step of Carrington's plan, Reegan successful forces the ambassadors to carry out attacks then escape before anyone can react. Attempting to stop the Doctor getting into space, Reegan sneaks into the space centre posing as an engineer, disables everyone in his way, sabotages the rocket and escapes before anyone notices. Then upon his return he manages to successfully kidnap the Doctor from right under Unit's noses. Reegan reveals he plans to abandon Carrington, and instead use the aliens to perform robberies, as between his strategic brilliance and their raw power no one on earth could stop them robbing even Fort Knox or the Bank of England.
- Narm Charm: The way the serial's title is displayed on-screen — starting with a zoom-in on "The Ambassadors", and then "Of Death" appearing in much bigger letters underneath a few seconds later — is so hilariously cheesy that "The (something)... OF DEATH" remains one of the Doctor Who fandom's most widely-repeated memes to this day.
- Signature Scene:
- The UNIT raid on the warehouse in the first episode. Originally conceived of as just a short sequence to pad out the episode, the production team ended up with more time and money to film it than they were originally expecting, resulting in one of this era's more fondly-remembered action sequences.
- Liz's attempt to escape from her pursuers across a bridge is also one of the story's most well-remembered sequences, as Caroline John not only performed some very risky stunts by herself, but even did so while she was pregnant (though in fairness, she didn't know this at the time).
- Special Effects Failure: This was the first Doctor Who story to make extensive use of Colour-Separation Overlay (CSO, or Blue Screen/Green Screen/Chroma Key as most people probably know it), and it's really obvious that they were still getting to grips with the technology. Just to name the most blatant example, halfway through the first episode there's a CSO monitor display. When the monitor is lowered away, however, the image on the screen doesn't lower with it, making it look less like a monitor and more like a screen that someone off-camera is projecting an image onto.
- Uncanny Valley: The Ambassadors. Astronaut suits possessed by a deadly alien intelligence so different to humans that communication with them is impossible.
YMMV / Doctor Who S7 E3 "The Ambassadors of Death"