You are cordially invited to Argentia, the galaxy’s most exclusive tax haven, to attend the funeral of mining magnate Carlo Mazzini. The memorial service will be followed by music, light refreshments, and murder!
Carlo’s heirs have come to say their final goodbyes (and find out how much they’ve inherited) but when a masked killer begins picking them off one by one, Argentia goes into lock-down, closed off behind its own temporal displacement field.
Can the Doctor, Nyssa, Tegan and Adric apprehend the murderer before Argentia – and everyone on board - is forever cut off from the rest of the Universe?
Serpent in the Silver Mask contains examples of:
- Air-Vent Passageway: Adric takes this as an absolute given.Adric: No secret passages, you said!Sofia: And it's not! It's a ventilation system.
- Animal Assassin: The normek in Frank Mazzini's room.
- The Announcer: Zaleb 5, who can't speak unless he's either advertising something or describing things like a game show host.
- Ask a Stupid Question...:The Doctor: Why would anyone on this station have an incineration beam?Nyssa: Well, what are they used for, usually?The Doctor: Incinerating.
- Bad Liar: Nyssa has never been great at subterfuge or undercover work, but Adric makes her look like a master spy in comparison.
- Bavarian Fire Drill: The Superintendent assumes the TARDIS crew are on Argentia for the Mazzini funeral and they don't correct him.
- Beast Man: Superintendent Galgo, a Killoran.
- Big Damn Heroes: The Doctor turns up in the TARDIS just before the others are sucked into a giant turbine.
- Blue Blood: Nyssa's shows through when she is the only member of the TARDIS team to not be impressed by Argentia, calling it "a tasteless person's idea of luxury".
- Boy of the Week: Joe and Tegan.
- Call-Back:
- Adric mentions Alzarius, and his brother, Varsh.
- The Doctor mentions his "stint" stuck on earth, not very fondly. He bemoans the UNIT canteen breakfasts.
- Call-Forward:
- One of Argentia's many stores is Henrik's department store.
- People really do remember Agatha Christie's books far into the future.
- Character Development: This story marks the point where Tegan admits to herself that she actually likes travelling in the TARDIS, and turns down Joe's offer of taking her home in a more reliable time machine to stay with her friends. By the time of "Black Orchid", chronologically not long after this adventure, Tegan will have also asked the Doctor to stop trying to get her back to Heathrow.
- Comically Missing the Point: Maria tells Nyssa that she had her son's eye colour altered to better match her sofa. When Nyssa exclaims how horrible this is, Maria agrees: She spilled wine on the sofa a few weeks later and could never find another one in the same shade.
- Didn't Think This Through: Most of Angelo and Sofia's plan was quite well thought out, but how did they not foresee the consequences of Angelo going back in time to kill himself?
- Distressed Dude: Adric gets kidnapped by the killer towards the end as a hostage.
- The Ditz: Peter and Paul Mazzini, who can't tell the difference between an uncle and a grandfather.
- Dramatic Unmask: Done to expose Angelo. Everyone is annoyed with the Doctor for insisting on revealing the killer like this, rather than just telling them who it is on the way to confront him.
- Dwindling Party: The Mazzini's start to be killed off one by one.
- Faking the Dead: Angelo, though with a twist: he really is dead, but only his past self.
- Foregone Conclusion: The whole reason the Doctor came to Argentia is because it's home to the crystals used in making sonic screwdrivers. Since we all know he won't get another one for a few regenerations yet, the Doctor's quest is doomed from the start.
- Heroic BSoD: Briefly, and mostly played for laughs, when the imprisoned Doctor wonders just how useful he actually is when his companions take care of all the detective work for him.The Doctor: I mean, obviously, I hope they're able to manage without me, but that begs the question: If they can manage without me, what's my purpose? Am I just one of those fondly-remembered school masters people thank in the introduction to their memoirs?
- Inheritance Murder: This is assumed once the Mazzini's begin to be killed off, but the truth is more complicated.
- Instant Expert: Nyssa, girl genius, is able to figure out exactly how a medical scanner works just by laying hands on it.
- Kill It with Ice: The cryo blasters.
- LEGO Genetics: The Mazzini's. Maria had her son's eye colour altered to match the sofa.
- Living Toys: Baby Chuckles, sentient dolls who were so creepily realistic nobody wanted to keep them, but so lifelike that no one felt right about burning them, so they were released into the air vents, where they swarm like bugs.
- Mrs. Robinson: Maria, attempting to seduce the Doctor.
- No Immortal Inertia: A strange variant with Angelo, who killed himself in the past. The time bubble prevents the paradox from taking effect, but once the bubble is broken, he transforms into his own shot corpse.
- The Nose Knows: The Killoran superintendent Galgo is able to tell identical twins apart by smell.
- One Dialogue, Two Conversations: The Doctor tries to puzzle out who the killer could be while Tegan tries to pour her heart out to him about Joe, neither one of them realizing they aren't actually having the same discussion.
- Police Are Useless: Though Tegan points out that it is somewhat justified, given the setting.Joe: Surely the superintendent has his best people on this already.Tegan: His best people? On a space station which had a zero percent murder rate until yesterday?Joe: Good point.
- Precrime Arrest: The murders are motivated because Angelo saw how his relatives would turn on each other to get the inheritance, so he went back to kill them all before they could kill him and other people.
- Red Herring: The missing painting.
- Running Gag: At this point in Big Finish, the Doctor bemoaning his lack of a sonic screwdriver would make a good drinking game.
- Teacher's Pet: Tegan calls Adric this for showing off to the Doctor what he knows about the sonic waveform crystals.
- Timey-Wimey Ball: The timeless nature of Argentia allows Angelo to kill his past self as an alibi and not be immediately erased by the paradox. He and his associate intend to ultimately seal Argentia away from the rest of the universe so that he won't be destroyed by the paradox once he leaves the station, but the Doctor is able to break the seal.
- Token Good Teammate: Joe is the only Mazzini not totally selfish, insane or murderous.
- Too Dumb to Live: The twins, Peter and Paul. Peter particularly since he managed to shoot his brother during a hair-pulling fight. Accidentally.
- Too Good to Be True: Tegan suspects this about Joe, wondering if he might turn out to be a Love-Interest Traitor. He doesn't.
- Uncanny Family Resemblance: All of the Mazzini's are "demi-clones", born from cloned genetic material and given a few twists "for variety".
- Unexpected Successor: Nobody was betting on Angelo inheriting the full nine billion credit fortune from his father, least of all Angelo himself.
- Unexplained Accent: The Mazzini's can mostly be told apart by their different accents. While it's established that they aren't exactly a close-knit family, it's not mentioned why their accents range from Yorkshire to Italian.
- Whole-Plot Reference: As mentioned in the behind the scenes interviews, this story is one big homage to Kind Hearts and Coronets.
