The Mummy episode is not exactly a high concept episode, but it still works well. In a way, the use of the Mummy is somewhat pandering to an audience. As had been mentioned on here previously from 1958 – 1977 classic Universal horror films (and other studios such as Monogram, etc) were released into syndication where they remained popular with younger audiences and adults who had grown up on the films and revisited their memories on the small screen. While the popularity of the monster boom peaked as a mega fad circa 1964 (Aurora Model kits which was famous for its movie monster kits earned upwards of $50 million in 1964) the films still remained popular with kids to a degree that classic monsters could be borrowed to draw an audience. (This is why the dopey werewolf made two appearances in season 3) The Mummy was borrowed and he was connected to a flimsy plot – the Mummy, a national treasure, needs to be delivered to a Middle East nation within a certain time frame to ease population tensions that have been stoked by the Soviet Union. Easing these tensions can (hopefully) stop the onset of a war in the Middle East. The Mummy doesn’t dig this plan and comes to life to cause the Seaview not being able to reach its destination in time. Yes, this is a WILDLY implausible episode but what makes it work is that the Mummy remains menacing, devious and scary. By keeping the Mummy serious and not campy the episode works as opposed to the werewolf episodes were silliness abounded so much that you couldn’t even remotely take the proceedings serious.