Here's everything we know so far about 'Stranger Things' season 2

Netflix has announced that its hit series "Stranger Things" is returning for a second season in 2017. But fans still have a lot of open questions about where the plot will go.

So who's coming back? What new thrills do show creators Matt and Ross Duffer have in store for us? And are we returning to the Upside Down?

The brothers have thrown out some hints.

Here's everything we know so far about season two.