Fimbulwinter has begun, and Ragnarok is at hand. Unfortunately, the gods who were supposed to fight in the great battle are long dead, leaving their descendants to act as their representatives. Thirteen-year-old Matt finds himself recruited to act as Thor, but he has no intention of letting the World Serpent kill him, no matter what his family wants. 
 I struggled with rating this book; while it didn't entirely appeal to me, I recognize that I'm not its target audience. Yet there are issues with characterization that I found disappointing for a Kelley Armstrong book (I'm not familiar with Melissa Marr's style), especially one aimed at older children or young adults. Specifically, Matt and Fen (Loki's descendant), spend a lot of time telling Fen's cousin Laurie that she can't help them because she's a girl. And while she verbally lashes back at them for their sexism, she hardly does anything. To be fair, most of the other characters are pretty much props; only Matt and Fen are fully characterized and allowed to do things, while everyone else exists to support their plans and push the plot forward. Even in the chapters from Laurie's point of view, she hardly gets any characterization. 
 While this is an interesting premise, and I appreciate that the kids aren't reincarnations and thus don't have the phenomenal cosmic power of the gods to make everything a bit too easy, the execution was rather flat.