* AdaptationDisplacement: To some degree, anyhow. Think about it: how often do you hear anyone refer to the original short story or radio play ''Three Blind Mice'' instead of the play?
** Although that's partially due to publishing of the short story being banned in its home country until the show stops running. It was, however, released in the United States.
* CrowningMomentOfHeartwarming: The ending. [[DoNotSpoilThisEnding We won't say why.]]
* FreudWasRight: Many viewers think that Christopher Wren is supposed to be gay, based on his mannerisms and finding Sgt. Trotter to be attractive (as a policeman), "terribly hearty", etc. Officially, he's not.
* ItWasHisSled: Averted.
** Not entirely; they give it all away at ThatOtherWiki, those killjoys.
*** They do at least acknowledge it just before they do so.
* SpoilAtYourOwnRisk: Ignored by the general public.