Foreshadowing can be a super handy writing tool. However, it ought to be used sparingly and carefully. Meg Cabot did not follow this rule in the creation of this novel. Almost every chapter ended with a dramatic bit of foreshadowing of the "had I known what would happen next..." variety. Sigh. Just put 'to be continued' at the end of each chapter and be done with it. There just was not any need for it. If you have to try to force people to keep going with a lure of future drama, clearly your book wasn't interesting enough. Really, I think this would keep the intended audience going without these constant, hackneyed warnings.
Another weakness here was the odd subplot wherein Pierce tries to befriend the popular kids at her school (who usually ignore the D-Wing, aka truobled kids) students of the school) so that she can make them leave her cousin, Alex, and his friend Kayla alone. These sections really do not seem to fit with the rest of the plot very well. I imagine the need for this might be clear later in the series, but, for now, they were rather obnoxious, largely because Pierce's behavior seemed both out of character and completely illogical.
So far, the romance in the series has been pretty much entirely uninspired. I do not ship anyone and I actually find Pierce and John's relationship to rather creepy and Stockholm Syndrome-ish. The ending is not a resolution, so much as a stop because this novel had reached the requisite number of pages.
Mostly, Abandon was not what I was hoping for, but I will still be reading the rest of the series for sure. If you need a beach read for this summer, Abandon will likely suffice.