The good thing about this book: very well written, full of action, well described characters and situations.
The bad: Book 2 in a series, and I do feel you have to read the first one to grasp all about Metro, a graffiti artist and her friends. They live rough and have traveled from Finland to Germany, where they try to save a mural by Banksy. There's a whole lot of things going on, as this small anti-establishment group are causing chaos with their painting all around town.
Probably this was a book that is too young for me, but all in all, quite interesting.