Accomplice

As with most Young Adult fiction, there are hit-or-miss dichotomies packed into this book. I enjoyed the novel, and it's become one of my transient favourites, yet I was constantly disappointed. If you enjoy dark stories, grim ones dealing with human flaws and failings, then I would recommend Accomplice. If you're just looking for a mystery, then I would probably suggest passing it over.
The narrator, Finn, is one of those hit-or-miss aspects. I don't relate to high-school tropes, and felt that their presence made for a clunky attempt at relating to other readers. The constant internal struggles with lying and pretending, and the observations about the adults around her caught my attention and gave me plenty to think about.
What kept me reading was the mystery; I was trying to predict the ending. The writing is done well so that despite constant filler, information is added on the basis of necessity. Tension was added every chapter with conflict and hints, and putting down the book for a few minutes just to consider everything made for a pleasant time.
On the technical side, the prose was acceptable but fluffy. This novel could very well be cut down to a short story, but I think that leaving in all the fluff helped in the end. It added a human touch and amplified the effect of the revelation.
For the mystery aspect, I was quite pleasantly surprised. Finn is the narrator, and is supposed to have the reader relate to them, yet Chloe is the main focus of the story. The plot and mystery revolves around Chloe's disappearance, and her plan to be rescued. It may seem hare-brained, but the ending is well worth it.

A spoiler about my thoughts on the novel:
This is a well executed novel and character study, chiefly about the two teens who commit what Finn calls a victimless crime. Corrigan made it obvious that the story was thought-through from the beginning, and not just a plodding story with no definite plans. It only hit me at the end, once I realised who and what Chloe is, how cleverly crafted Corrigan's book is. From the start, Chloe has a plan, and at the end of the book it's still ambiguous what exactly it is. Using Finn as a narrator to offer glimpses into Chloe's character made the rest of the story retroactively superior. Another compelling factor is the feeling of being strung along, caught up in lies and made to go along with them from sheer inertia. It's a dead-on feeling that fits teenage years.