4 stars. 
 I have so many mixed feelings about this book. Start with the positive? Loved Rick's writing (for the most part). Magnus' voice was so funny, sarcastic, sassy and yet so endearing. A lot of the characters were really fun, interesting and diverse. His "sidekicks"/friends brought a lot to the story that I loved and it all climaxed SO NICELY at the end of the book. Honestly, the ending just made me feel so bubbly and happy - it was very very heartwarming. 
 The middle dragged a bit for me, however. I didn't really feel too inclined to read the book sometimes, which was a shame. Another thing that irked me a bit was some of the more "silly" humour (that's what I'd describe it as) which I found pulled me out from the story a bit. For example there are several pop culture references that seemed a bit out of place - it reminded me quite a bit of the Hitchhiker's Guide when it came to some of this more "silly" humour. I definitely get how some people would love that about this book, and I think I might have even loved that when I was younger, but I think I've turned into a boring person now who doesn't find it funny anymore. Lastly, sometimes I was a bit confused as to what was going on, but I think this is just because I'm not familiar with Norse mythology AT ALL and also I tend to speed read sometimes and skip details (IM SORRY) but nonetheless this book was definitely a really good introduction to something that I was not previously knowledgeable about. 
 I was most likely going to give this book 3-3.5 stars because some of this silly humour and just that I didn't feel that attached to the story in the middle BUT OH MY GOD THE ENDING CHANGED EVERYTHING. I had no idea how attached I got to the characters till the end, and as usual Rick used his magic ability to seamlessly and beautifully weave the prophecies in with the story and drop little hints along the way, which made the conclusion so so so satisfying. 
 TL;DR I had some issues with some aspects of the writing but most of those may have just been due to the middle grade genre which I haven't properly read in a really long time. I felt like the conclusion was super satisfying, though, and the book was definitely worth the read because of that. Also Magnus is such a good, relatable character who I love and his friends are also so so endearing. If you love Rick's book, READ THIS.