Fans are speculating about the plot of a tv show, with various theories being discussed online. The show in question appears to be either "Sherlock" or "Stranger Things", as both are mentioned in the context of fan theories and speculation about upcoming seasons. Theories about "Sherlock" season 4 and "Stranger Things" are being shared, with some outlets discussing the possibility of a secret episode, while others are analyzing the potential darkness of an upcoming season of "Sherlock".