Somewhere in the multiverse, another me is giving this 5 stars. 4.5/5 stars. 
 Definitely 4.5, not 4. 
 This review was originally posted on my book blog. 
 This review will be spoiler-free and therefore brief. 
 Dark Matter brought back strong memories of a TV show I loved: Quantum Leap. It's very possible that readers under the age of 30 will have no idea what I'm talking about but trust me, that show was brilliant TV (particularly for the standards of the late 80s and early 90s). Obviously there are more differences between Dark Matter and Quantum Leap than similarities, but the idea of a man stranded outside his own life, desperately trying to get home, is a powerful one. It worked for Quantum Leap and it works just as well for Dark Matter. 
 The book also has fantastic pace. The set-up is brief and then we're plunged straight into the action. The momentum is so gripping that I read through to page 290 in one sitting. Unfortunately, after such a build-up of tension, I felt the last 50 pages or so were a little slack. I'm not even sure why. Thinking back over what happened in those pages, I should have been on the edge of my seat, so I don't know why I wasn't. 
 All the theoretical physics is thankfully understandable and, mercifully, not really that important. At the end of the day - like Quantum Leap - this all comes down to character. We have a main character we care about - Jason - and he is separated from his family. He fights tooth and nail to get back to them and we're with him all the way, we want him to succeed. That is why this book works. So don't worry if this sounds too sci-fi for you and you don't usually read sci-fi. Give it a go! 
 Overall: a gripping struggle-against-the-odds story with a smattering of mind-bending science. Go on, give it a try!