I hesitated reading this for so long because I thought I was done with mirror worlds, specifically ones that take place in just one city, but Schwab's writing sucked me in. The magic system and the history of the different Londons are interesting and distinct thanks to magic and the characters, particularly Kel and Delilah are awesome.

I'd actually give this 4 or 5 stars, but I really disliked the audio version. It was Schwab's story and worldbuilding that made me grit my teeth and power through the audio. Pick it up, but don't listen to it.