There is no other way to put it other than this book tore my heart out and then stomped all over it.Hazel is a seventeen-year-old girl (I think) who is a remission from a form of cancer that causes her lungs to be dysfunctional to the point where she needs to cart around an oxygen machine to live. She is forced to go to a Cancer sufferers support group and that is where she meets Gus, a teenager, who is also in remission from a different type of cancer.Cancer is something you hear about, but unless you have seen a family member or someone you know go through it, you don't know what it's really like - for the sufferer or the family/friends. It gives me the impression of playing 'Russian Roulette' - especially if it's hereditary or you're in remission from it. To live in fear that you, or someone you love, will fall victim to it and then lose the battle against it has to be horrifying. That's the thing that keeps going through my mind.And that's what Hazel, Gus and some of their friends live with.To be honest, I have never felt such an attachment to two characters in any other book, apart from possibly Night Road by Kristin Hannah. I think it was because it was so easy to imagine it was me or someone I loved who had it - instead of Hazel and Gus, two fictional characters. This book was so bitter-sweet. Even though I knew what was coming, I held out hope that it wouldn't. Admittedly, there were some scenes in the book that made me raise my eyebrows, but it wasn't enough to make me focus on it - not when a real tragedy was unfolding before my eyes.I loved Hazel's snarky, sarcastic tone. It was believable, and it was easy to see why she would be that way. She didn't strike me as depressed, but rather accepting of what she had. She was a fighter though and very much the teenager in that she didn't want her parents stalking her every move. She was friendly and supported her friends where she could. And,although wary, she had a very open heart - she had to have to let Gus into it.Gus was my favorite character. He had his faults, yes, but he was a fighter as much as anyone else. What he did for Hazel was so sweet, and just another thing that broke my heart as I read on. He was loyal to his friends, but at the same time he did egg them to do things that wouldn't usually be okay. I could ramble on about him for awhile but I'm scared of revealing spoilers.There were also many great supporting characters too - like Isaac. He was a friend to both Hazel and Gus before they actually met. He was part of the support group. Peter Van Houten was another interesting character. He was an ass, but he had good reasons. I felt a little sad for him.There was only one thing that I could nitpick about. While Gus sounded somewhat like a normal teenager, Hazel, at times, spoke like she was a spouting words from a dictionary. I understand she was in Community College and that there are different levels of vocabulary out there, but it just didn't seem natural to me. Anyway, I still give the book 5 out of 5 stars simply because I loved it.