'Stranger Things' fans get a first look at season 5 with on-set moments and cast reflections in Netflix's sneak peek. Millie Bobby Brown notes that she was a 10-year-old actress when the sci-fi series began, and she's now 20 years old as the cast and crew are half-way through filming its final chapter. Finn Wolfhard, Maya Hawke, Jamie Campbell Bower and more stars are behind the scenes as they hint at what Hawkins-heads can expect from their last episodes.