The CW's Supergirl has taken the Superman canon and turned it on its head, giving it a whole new life, but that means the show totally leaves us guessing when it comes to, well, a lot. There's still so much we don't know about the show's badass superheroine and her Kryptonian heritage, but that's just the tip of the iceberg – that's also why so many fan theories about Supergirl and its characters have popped up over the years.
Are Supergirl and Smallville parallel universes? Is Lena Luthor really a good person? What's the deal with Mon-El? How does Batman fit into the CW show? Will Saturn Girl die in order to make way for Karamel once again?
There are plenty of mysteries on Supergirl, which means there's a dedicated group of fans trying to solve them. Some Supergirl fan theories are a bit far out – like one about Saturn Girl using mind control on Mon-El in order to keep their marriage going – while others make perfect sense.