10 Star Trek Episodes That Completely Ignored Convention
1. If Memory Serves
If Memory Serves is a second-season episode of Star Trek: Discovery, which begins with a 'previously on Star Trek' montage. Now, while there had been plenty of 'Previously ons' in Star Trek's history, they hadn't shown two different incarnations of the same character, from two different shows before.
What this means is that, for the first time on television, Star Trek showed two different established main actors playing the same role, albeit more than fifty years apart. Jeffrey Hunter appears, via archive footage, as Captain Pike. Anson Mount then plays Pike in the episode proper. The Cage and Star Trek: Discovery are tonally about as far apart from each other as night and day, but this inclusion spoke to the audience, reminding them that it is all part of the same Star Trek.
Using archive footage has been done in Star Trek before to great effect, particularly in Trials And Tribble-ations, but If Memory Serves manages to tool the footage in a way that brings the audience in on the joke while honouring the differences as well. The only thing missing from the episode was a photo of Bruce Greenwood or Sean Kenney, and the set would be complete.