- British Stuffiness: Lady Penelope and Jeremy Hodge's failure to panic when shut in a room flooded with Deadly Gas. While banging on the door, Jeremy even shouts "Open this door at once, we're British!"
- Computer Equals Monitor: The villain appears to completely disable the railway power cutting system just by shooting the display. Given these were 1960s-style computers where the display is built into the fascia, this may not be as improbably as it seems.
- Chained to a Railway: Of a sort.
- Deadly Gas: How Dr. Godber tries to dispose of Lady Penelope and Sir Jeremy at the Archives in Paris.
- Elaborate Underground Base: The villains lair is inside a mountain, next to the train tunnel. We don't get to see how big the whole thing is, but it is clear that they can control all train traffic in the tunnel from there.
- Heel Realization: During the final showdown, Roache, Dr. Godber's henchman, seems to realise this plan has gone too far and, with persuasion from Jeremy Hodge, reaches for the button that stops the train — unfortunately he is shot.
- Missed Him by That Much: The attendant, who got thrown off the train, passes out next to the road just in time for Parker to miss him.
- Reluctant Mad Scientist: Professor Borinder, a shameless Einstein expy.
- Sadistic Choice: Hand over the formula or save the girl.
- Shown Their Work: The rocket launch sequence at the beginning is more realistic and based in NASA procedure than most you'd see in today's fiction. They even foresaw a hold-down system, which SpaceX has only just invented now.
- Tap on the Head: The attendant, in league with the bad guy but about to spill the beans, is on the recieving end of one and gets thrown off the train.
Recap / Thunderbirds S 1 E 3 The Perils Of Penelope
Lady Penelope goes on a dangerous cross-Continental trip to discover what has happened to a brilliant scientist - only to discover that a megalomanical lunatic has kidnapped him in an attempt to discover his research. In order to persuade the scientist to comply the villain presents him with a Sadistic Choice - the formula, or Lady Penelope!