Is anyone watching this? I finished season two about 6 weeks ago but I'm wondering if I should just rewatch the first two seasons before starting the third.

If you're unfamiliar with the show, I can't recommend it highly enough. It's probably the best TV show, of any type, that I've ever seen. Here's the original trailer, but there's SO much more than what it shows. In the words of @Bezarius who recommended it to me:

The German show Dark is incredible. I just finished watching the first season this evening and it's the most perfect season of television I've seen in a long, long time. Literally the only thing I would rate alongside The Sopranos or The Wire. It has it all - complexity, deep philosophy, theoretical physics, horology, sci-fi elements, brilliant characterisation/acting, unpredictability, great dialogue and masterful pacing. Check it out.

A word of warning though. DO NOT watch it in English, The English voice acting is atrocious.