Who really calls the shots in The Upside Down? Vecna? The Mind Flayer? Who came first? Let's take a look at how these two otherworldly monsters are tied to each other and what it means for the heroes ...

She soon realized that wasn't entirely the case. "I was like, 'My big Joker card is at some point we're going to have this huge Mind Flayer deploy and it's going to encompass the entire theater. The ...