There’s a famous thought experiment called Schrödinger's cat, which states that if you put a cat in a box with some poison and come back to it an hour later, the cat is (in a sense) both alive and dead.
Sounds like something Missy would do, right?
Doctor Who’s unanswered mysteries work in much the same way. We might speculate what happened to so and so, or whether that thing really did happen the way we imagined. But if the theories we come up with are just as credible as each other, we can never know for sure which one is correct.
Some questions do have a definite answer. What is Bad Wolf? Who is Missy? What’s the Flux? However, where things like the Doctor’s name or origins are concerned, there’s no one explanation that’s going to appease everyone. Sometimes it’s best to just let fans make their own minds up.
And frankly, we wouldn’t have it any other way. Indeed, the open-ended nature of these mysteries is what makes them so compelling.
The show does occasionally revisit seemingly-forgotten plot threads (like Ace and Tegan in The Power of the Doctor). But more often than not, if a question goes unanswered, or a mystery unsolved, it’s probably going to stay that way…
10. Who Was Jim The Fish?
Like the Singing Towers of Darillium, many of the adventures contained within River Song’s diary have subsequently been elaborated upon.
The crash of the Byzantium, which received its first mention in Silence in the Library, was eventually depicted two years later in The Time of Angels/Flesh and Stone. Meanwhile, two accounts of the picnic at Asgard exist in prose, taking place with either the Tenth or Eleventh Doctor.
But one diary entry yet to make it to screen is the Doctor and River’s encounter with Jim the Fish – an aquatic ally who remains shrouded in mystery.
Jim was first alluded to in Series 6 opener The Impossible Astronaut, ultimately serving to highlight the age difference between the older and younger Eleventh Doctors more than anything else (the older has met Jim, the younger has not). But as Doctor Who fans, we need answers!
Was Jim an actual fish, a fish-human hybrid, or something else entirely? All we’re told is that he’s “still building his dam”, which suggests something slightly more sophisticated than your average pet goldfish.
As if to rub salt in the wound, the only other time the character is referenced is in The Husbands of River Song, when Flemming remarks that “We all know Jim the Fish!”. Erm, do we?
After 12 years and still no concrete answers, it feels like the mystery of Jim's importance will never be addressed. Cod-damnit!