A murdered Conspiracy Theorist leads Holmes and Watson to discover that someone is killing the participants in a set of military war games.
Tropes:
- Conspiracy Theorist: Sherlock reveals that one of his hobbies is trolling conspiracy theorists by making up ridiculously outlandish stories and seeing which ones they'll believe. This episode's plot kicks off when Sherlock finds the moderator of one conspiracy theory website dead. Holmes correctly assumes that the murder was to cover up that one of the theories was actually correct, which is how he ends up discovering the Red Team.
- Flipping Helpless: Sherlock uses Clyde the Tortoise as a paperweight by flipping him upside-down. Joan disapproves and sets the poor tortoise back on his feet.
- Leave No Witnesses: Whatever plan the Red Team came up with during the war games exposed a crucial flaw in US national security, one that's so big the team leader decides that it would be safer if everyone who knew about it is dead.
- Never Suicide: Zapruder a.k.a. Len Pontecorvo is found dead, hanging from his gym equipment in what certainly looks like a suicide. Sherlock finds clues that prove Pontecorvo couldn't have killed himself, meaning his death was staged to cover something up.
- Pet the Dog: Sherlock takes Pontecorvo's pet tortoise Clyde home, noting that he'll starve to death if left behind. Sherlock repeatedly claims he's only doing it so he can eat Clyde once he's fattened up, but by the end of the episode Clyde is still alive and will become a Team Pet for the rest of the series.
- "The Reason You Suck" Speech: Gregson gives one to Sherlock for his actions with Moran in the previous episode. He calls Sherlock out on his arrogance and selfishness and then punches him in the stomach for good measure.
- The Unreveal: The security issue discovered by the Red Team, something so bad it caused Harold Dresden to kill people, is never revealed to the audience. Sherlock claims to have been told it but admits to Joan that whatever he told Dresden was an educated guess.
