Written without spoilers.
With the Mortal Instruments trilogy all wrapped up Clare decides to expand the series and bring back all our favourite characters. I was originally hesitant, I enjoyed all of the first books but wasn't sure what else she could possibly to bring to the table. Was I disappointed? No, but I do have a bone to pick with Clare.
Clare's books are books I enjoy to read and this installment was no different, however my main problem with it is there isn't a lot of pay off. There's no satisfaction when you reach the end. In a book that is part of a series I expect it to accomplish two things, it needs to have wide story arcs that expand across the whole series, but it also needs mini-episodes, arcs that are resolved in the book itself. Otherwise an installment doesn't feel like a book in its own right, but just a fragment of a larger work. That's what Fallen Angels felt like to me, it doesn't stand on its own.
Understandable maybe, after finishing City of Glass everything was wrapped up so neatly that Clare is now forced to open some more doors. And does she ever! There are a ton of loose ends and question marks all over almost every young characters life.
A final qualm, the main conflict which we find towards the end of the book, which really sets up the rest of the series felt recycled. I still think it will work, just I felt a little disappointment when I realized "Oh, this is how she's going with it".
An enjoyable read overall, I just wish we'd had at least a couple minor resolutions.