When it is a YA series, I usually read the first book only, no matter if it was good or not. If it was good, I don't wanna be disappointed. In this case... like hell I won't read the sequel! This book was so good, so exciting.
I did not care for the team as much at first. They were all too suspicious. Glum. I saw it as a bit of a joke that they were all between 15 and 18 years old. Too young for having such a mission. And be so bad-ass. And sometimes cold-hearted. And looking like a devil with a cane, and be the perfect thief, and planning always the best and impossible plans (ok, all of these are mostly about Kaz, the least realistic character among the 6 of them. And also the least likeable) Anyway...
First I started to respect them, then to love them. 4 boys and 2 girls. Kaz, the chief, with his genius mind and quick hands. Has a dark past, made him hard and cold. Seems like he is at least 29/30-years-old (but he is 17... ha!) Jesper, his right hand. Excellent with guns, also a Grisha-in-hidden. I don't remember his age, but is around 18 but is written like he is 28. Inej, The Wraith. The only one who Kaz truly trusts. She is 17, but is written like she is at least, 23. Nina, beautiful Nina, with an amazing power. She is around 17 too, i guess, but she is written like she is 25. Matthias, the one who had a grudge against Nina and her kind, but can't really hate her. He is 18, but he is written like he is 27. And finally Wylan, good at drawing and son of a powerful man. He is the youngest at 15, but he could have been 18. They form this team to make an "Ocean Eleven" mission; get into Ice Court and take an important scientist from there. The whole adventure was excellent, no slow pace, full action, and all 6 of them were indispensable for the break-in. Not one of them was more-or-less; certainly not the girls. The girls not only are resourceful but strong and intelligent.
I love the bond between the team. I like the friendship between the girls. The distrust between the guys, but remaining loyal to the end. I love all 3 couples. Kaz' and Inej's is kinda painful; Nina's and Matthias' kind of doomed; Jesper's and Wylan's just beginning to bloom.
The weak part for me were: 1) the beginning. I wasn't really hooked until they start their mission. 2) many flashbacks, although I get that they were important for the story, for us readers to understand their past and what motivated them. 3) the main one: their ages. It seemed a bit ridiculous that a bunch of kids between 15 and 19 were so lethal and bad-asses and calculators and excellent at such a dangerous mission. It would have been a lot better if this wasn't a YA book and the characters were all between 25 and 30. I guess that age is old for a bigger audience, but still, it didn't make sense.
Now, for the sequel.