The Wife Upstairs by Rachel Hawkins: opinion.

An entertaining suburbian mystery about rich people who have everything and want more and poor people who have very little and also want more. Both haves and have nots are willing to do whatever it takes to fulfil their dreams. It's a quick read with some surprising twists I didn't see coming and although the rest of the plot was quite predictable, I enjoyed reading it. 

However, I had to read the ending twice because I couldn't believe my eyes. The Hallmark movie style ending (and don't get me wrong, I love Hallmark) was incredible. If you want to enjoy this story you'll have to suspend your disbelief.