This TV series is from a teen book, and so it has (only slightly angsty) teen heroes in the form of Malyen Oretsev (Archie Renaux) and more importantly Alina Starkov (Jessie Mei Li). It has a very evil big-bad, the cause of everything terrible in their world. And it has writing that traverses the range from idiotic to sublime.
Alina and Mal are friends, with a very strong bond having grown up together in an orphanage in the country of Ravka. They're shipped off to the army together, both soldiers - he a tracker, she a cartographer. Until - in the middle of the first episode, we find out that she's a Grisha (a "witch" by another name) and the legendary "Sun Summoner." Which appears to be good, as her country is divided in half by "The Shadow Fold," a large area of perpetual dark that's hard to cross and full of nasty creatures. She's escorted to the highest ranking Grisha in the country, General Kirigan - a descendant of "The Darkling" who created the fold, who aspires to undo the work of his forebear. And "Sun" is what's expected to destroy the Fold.
We also meet The Crows, led by Kaz Brekker (Freddy Carter) who owns a bar - but has a plan to make a million, if he can only kidnap the Sun Summoner. And, not co-incidentally, get revenge on Pekka Rollins, a mob-boss who has done him some unspecified but horrible wrong. Kaz is accompanied by Jesper (Kit Young) who's exceptionally good with guns, and Inej (Amita Suman) who is extremely good with knives and very good at getting in and out of places.
An example of the brilliant writing: at one point, Alina is trying to escape a castle, and she crawls into a trunk attached to a carriage. That just happens to be the very carriage belonging to the people who are looking for her. This sounds at first like exactly the kind of staggeringly improbable happenstance that puts me off many stories. But in this case, there was only one carriage because of what was going on, it was the one that had to be there and it was the one she had to get into. It was blind luck ... but it wasn't improbable - in fact, it almost had to happen.
Another nice feature is the political and social complexity: there are several countries in the immediate area, with different cultures and traditions. There's discrimination, based on race (notably, Alina is part "Shu," and thus despised by many) and abilities (Grisha are feared everywhere, and loathed as heretics in most countries except Ravka where they've become tools of the army). A lot of stories feel like the creators were so focused on their main character that they never thought about the world around their characters except as to how it could make their story work. But this world (which the fans apparently call "The Grishaverse") is extensive, complex, and seems to be well thought out.
But some of the writing gets very sloppy at times: among others, the overused you-think-he's-dead-but-he's-not crops up at the end of the season.
Despite some stumbles, the charming characters and the often good writing make this an enjoyable show to watch.