It's a YA novel written about the Marvel Cinematic Universe. Don't expect Anna Karenina.
I did appreciate the structure for a number of reasons. Tony Stark's relentless, persistent attempts to upgrade his armor and launch monitoring satellites into outer space begin the book. Peppered in between are stories focusing on Captain America, Thor, Dr. Strange, and the Guardians of the Galaxy. Stark's tale continues as an interlude between each. I also like that each of the narratives are told in close-third-person through the perspective of a peripheral character: Happy Hogan for Stark, Natasha Romanov for Cap, Heimdall for Thor, Wong for Strange, and Nebula for the Guardians.
The weakness, however, overwhelm the book. While the Cap and Strange sections introduce a new adventure unseen on the big screen, the Thor and Guardians yarns are just a rehash of previous movies. Even the original stories contain a similar synopsis of what has already been. In all instances, there are moments of dialogue lifted directly from the screenplays. Interesting to see it all through alternate eyes, but it still feels redundant. I was hoping to have more narrative addressed, specifically surrounding Thanos: what happened when he attacked Xandar to obtain the Power Stone, and what went down when he and his minions attacked the Asgardian spacecraft? The Mad Titan only makes an appearance when bickering with Ronan, scenes again we've already witnessed in the first Guardians film.
A final gripe is the lack of a couple of central characters. I've always loved Spider-Man, and the book could have deepened the mentor/surrogate father relationship he and Tony have. How great would it have been to see them team up, even to tackle some low-level baddie from either of their respective rogues galleries? Instead, there are only brief mentions of "the kid," that he's from Queens, and has "weird insect powers." I know that this is not so much the fault of the author; rather it's undoubtedly part of the intricate fine print of the agreement between Sony and Disney. Still, maybe with a little negotiation and perhaps some royalty percentages diverted, it could have made for a more interesting read. (For the record: Sony, just come off the property already, would ya? Think how much better Venom would have been when tied into the MCU.)
There is, however, no excuse for the utter absence of the Black Panther and Wakanda. Just one minor line about T'Challa and Bucky being stashed in his kingdom. I'm sure the book was written well before the runaway success of the Back Panther movie, but they did know what a major player he would be in Infinity War. There is simply no excuse to cut someone of this magnitude. Again, if I had only twenty pages of T'Challa, Shuri, Okoye, and crew tangling with Moses Magnum or Madame Slay, I would have been forced to add an extra star to the review.
Long story less long, I got the book because I am working with a colleague on a journal article about Infinity War. I was hoping to find some new insight or a different angle. Instead, I spent a couple of hours exploring the fringes of the MCU. I was entertained but in no way further enlightened. If you are about to watch/re-watch Infinity War and need a refresher on what led up to this cinematic event, the book is a quick, informative way to catch up. It's over 300 pages, but the print is big and the style simple enough that it reads at lightning speed. This would be much quicker than attempting to take in all 20 movies. Otherwise, I'd opt for a book that is better written and has more depth.