If you haven't watched Stranger Things yet, then what are you waiting for? It's one of the standout series of the summer, possibly even the year.What makes Stranger Things so special is that it combines fantasy, curiosity, and science to create a believable fictional world. The characters, most of whom are kids, are refreshingly authentic. The four main friends — Will, Finn, Dustin, and Caleb — are innocent suburban boys, thrown into the adventure of their lives. The genre-bending horror series is more mind games than gore, and more '80s nostalgic than tragic.The only downfall is, now that season 1 has been sufficiently binged, we're in withdrawal as we wait for news of season 2. To pass the time, we're rounding up the best theories about the series finale.Matt Duffer, one half of the Duffer brother duo behind the show, told Variety that the plot of the series is only going to get darker and more intense with the next season (which is rumoured, but not yet finalised.) And that as the show goes on, the characters within it will be trying to piece together the mystery with theories of their own. "They’re very weird, and the weirder it is, the more inexplicable it is, the scarier it is," he told the site.Weirder? Scarier? Count us in. Now, let's get to theorising.