Lorenzo is a 14 year old who realizes very early on that he is slightly different to the rest of the herd and if he is going to be socially accepted he better fit in and do so quickly. He is otherwise going to be bullied and picked on all the time (what is it with bullying in the schools. I still don't get it!). He also has to keep his parents happy. They want to see him assimilate easily, have school friends pop over, get invited for sleep overs or spend the day type of events and be in their eyes a "normal" kid.
To please them he invents a weekend invitation away on a skiing trip with friends and instead holes up in the attic. He plans this well and provides himself with everything that he would need. His well planned holiday alone gets blown away with the arrival of his step sister Olivia. She is the daughter from his father's first marriage, not close to anyone in the family and one who has more or less cut off links with the whole family. She is sick and needs a place to just stay. Reluctantly at first Lorenzo allows her to stay. He has no choice because she is too sick to move away.
For me Lorenzo was quite a difficult character to analyze. He enjoyed the facade of being the kid his parents wanted him to be, he also knew that he wasn't, he also knew his survival amongst his peers depended on his fitting into what was considered "their norm". There was never any moment for Lorenzo to be Lorenzo. This situation was complicated further by Olivia and together they had to cope with situations they did not envisage.
Lots of unanswered questions in a short book. I cannot say I thoroughly enjoyed it. I generally do not like dark characters and the fact that a child of fourteen has to do so much to sublimate his own character depressed me. I think I am just too old for this kind of read!