tl;dr
Very interesting magic system that I'd love to more know about, and some cool legal drama. Despite multiple POVs, only the lead character got significant development.

About:
At seventeen years old, Cayder knows exactly what he wants for his life. He intends to be a prosecutor, putting away criminals who use the forbidden time-altering magic known as edem. He lands an apprenticeship with a public defender, hoping to use his time there to learn the tricks of his future opponents. But his world view shifts suddenly when his first three clients all test his own ideas of right and wrong.

What I Liked:
The magic system with edem and time-shifting caught my attention immediately. I haven't read anything quite like it, and it was cool seeing all the creative ways it can be manipulated. I'm surprised how much I enjoyed the courtroom scenes. Those are typically my least favorite part of a book, namely because they seem to rely on the main characters suddenly getting very stupid about things. In this case, both the prosecution and the public defender were very competent, and the twists in the case felt earned rather than contrived. For the characters, Cayder gets the most page time, and I think that really pushes him ahead in terms of development. He's likable, and his capacity for learning and change make him a great lead. The other cast members vary. While Jey is set up to be the roguish troublemaker with a penchant for acting, he doesn't actually get to show off very much, and I feel like he isn't given enough to do until he finally gets looped into the main plot. Leta is supposed to be precocious, but sometimes comes off as stupid in a frustrating way. I appreciate her desire to know the truth, but she didn't make a lot of smart choices to get there. Elle is the character I want to know most about. There's not a lot done to build her background - only her current goals. Hope we learn more about her in the second book. Kema is probably my favorite character - her personality and history are very compelling. The plot takes some time to get going, setting up what feels like separate threads, then slowly weaving them together in sometimes surprising ways.

What Wasn't for Me:
The title is not kidding. There are lots of liars in this book. And lots of lies. Maybe too many? Is that possible? Some reveals felt like they were held back on purpose for no reason other than they needed to come later.

I know Leta and Cayder had drifted apart, but why would she hide the truth about her death mark for so long? "I killed a guy because he was threatening me," seems like a much better defense than "I killed three hundred innocent folks because I was doing forbidden magic."

The villains of the piece are not very well-defined. While they posed a believable threat, there's not a lot I can say about them except the leader seems like maybe he has bad intentions? The sales text indicated this would be good for fans of Six of Crows, which pointed my expectations in the wrong direction. There isn't exactly a mastermind heist going on here, and the leads barely get to know each other by the end. The leads also largely lack the ruthlessness of the Crows. Go into this expecting a story about a bunch of kids in over their heads just trying to figure out a magical conspiracy, and you'll probably have a better time.