The first book I've read from Ryan Graudin was Wolf by Wolf which thoroughly impressed me. The author created an alternate reality post World War 2 in which the Axis Power won the bloodiest war in human history. With that premise, I didn't think she'd be able to top it. But lo and behold - another time-related world has been created by her genius and it's nothing short of amazing! 
 I loved time-travel stories and I am an avid fan of history so this is definitely a double-win for me! 
 As for its characters, I thought it would've been tricky for the author because of the multiple point of views of most, if not all of the characters in the book. Usually, I tend to veer away from such style but Ryan just know how to do it right. I love the core team comprising the Invictus. They are all likable except for one. There's Far's cousin Imogen whose penchant for hair color is the focal point of her character aside from being the Historian of the team. Gram is the genius engineer. Priya is the medic and Far's love interest. And their newest member, Eliot - the mysterious girl who annoyed me to pieces. Her character just didn't clicked with me no matter how the author tried to justify her existence. 
 One of the focal points of the story is its time travel aspect throughout history. There wasn't much really. Most of their adventures were off-page but I loved how Graudin tried to insert minute details in them . I wished that some of them were longer but I appreciate the fact that the author didn't indulge too much because methinks it might drag the story somehow. 
 The ending was a bit anticlimactic but satisfying nonetheless. I felt some sort of relief when I finished it but really, I wanted a longer epilogue. Or maybe, I just want more from this universe because it's just so fascinating. I cannot recommend this highly enough and I think at this point, overall - it's got to be the best book I've read this year. 
 Rating: 5 out of 5 stars