A Darker Shade of Magic is such a unique addition to high fantasy in a way that mixes historical urban fantasy and complicated magic systems. 

Kell is an Antari, a rare magician that is able to travel between three worlds, that he has named Red, Grey, and White London. Black London was a fourth world but was overrun by magic and deteriorated and affected all the other worlds. Now magic only exists in a healthy form in Red London, it's bloody and rare in White London, and Grey London is completely magic less. Kell is from Red London and apart of the royal family there, often doing business on their behalf. Kell finds interest in different artifacts across the Londons and becomes an unofficial smuggler as the only one able to travel between them. Lila Bard is an aspiring captain and current infamous thief in Grey London. She feels like there is adventure to be had and so much more to her life, which becomes true when she meets Kell. She discovers magic exists and both characters are thrown together when a deal goes wrong for Kell. They both now face the responsibility of protecting the Londons from a dangerous magic.

I was seriously surprised how much I loved this. Based on the synopsis and characterization as a portal fantasy, I didn't think this was something that I would enjoy too much. When starting, you are thrust in the book without background and pick up things over time. Yes it has a slow start, but once you start to learn about their world, it develops into a fast-paced tense race. Kell is competent and interesting as a character, but Lila is my absolute favorite. She holds her own despite not having magic and matches Kell in her cleverness. Her one-liners and humor absolutely help break up the tension, but it isn't cringey in any way. Her and Kell's banter was a highlight to this book. 

The magic system is very interesting, but I feel like I didn't get a good grasp on it because so many rules were changing between Londons and the introduction of the Black London magic. I feel like this will likely be fleshed out in the further novels. The pacing overall was amazing and it retained a tense and gritty atmosphere. Once the plot was moving, all you could feel were the stakes building for Lila and Kell. 

I thought the end of the book was great, but I am curious how the next ones develop. There are a couple areas not wrapped up, but it did feel like a standalone. I am curious to see what happens next when I continue!