(3.5 stars)Lena lives in an America where love is viewed as a disease which corrupts and destroys both people and societies. Since childhood she has been bought up to believe that love is dangerous, and that the 'cure' is what will make people safe. 'The cure' is seemingly an operation that removes any kind of real feeling from a person, afterwards you are 'paired' with another person and will be happy forever and ever. Lena cannot wait until her operation; she has been defined by the suicide of her mother and longs to be free from her past. However, the day of her evaluation for the pairing, she spots a boy standing on the observation deck above her room. This boy is Alex, and Lena does the unthinkable-she falls in love.I've said before that I treat Young Adult fiction with caution, however, Delirium has received a lot of good press and I quite enjoy dystopian novels; so when I spotted it in Waterstones I decided to throw caution to the wind and pick it up. And I'm glad I did.It took a while for me to get into the novel; but I liked the little touches that Oliver put in from the very beginning. At the start of each chapter is a quote from either 'The Book of Shh', a rulebook for society, 'Genesis: A History of Humankind' and other 'academic texts' which describe general rules or 'history' for the society. However, once the plot got really started I found myself totally gripped by the novel and unable to put it down. I'm not entirely sure how Oliver did it; she used relatively simple language throughout and yet I could feel my heart beating faster when Lena was getting nervous or making discoveries about society and the final pages, despite delving a little bit into melodrama, made me feel unable to put the book down.Perhaps one of the greatest thing about Delirium is that Oliver manages to tap into teenage feelings without being overly dramatic. The descriptions of Lena falling in love felt truthful, without being overly cheesy.Lena was a very sympathetic character, and as the novel is told from her perspective, we get an insight into her development from obedient member of society, to being desperate to escape from its confines. As a love interest, Alex was well-formed; we get a good look into his back-story as opposed to him just being a dashing bad boy, Oliver lets him have some vulnerability as well. Another favourite character for me was Hana, Lena's best friend, a vibrant, confident young woman who also becomes aware of the false world around them.I found Delirium a good, fast-passed novel which has a very dark undercurrent. The ending for me wasn't the massive cliffhanger that some people have interpreted it; I personally feel that Oliver could have left it at that and it would still be a fine book. However, the sequal Pandemonium will be released next year; and it'll certainly be interesting to see what the novel is going to be like.