This book was written by the same author as Big Little Lies, and it follows the same format. There is a big event that changes everything. The narrative jumps back and forth between the time before the event, the time after the event, and the night of the BBQ (the main event). Moriarty draws out the big reveal, just like she did in Big Little Lies. I will say I was anxious at first to find out what happened, and it made me spend more time reading just so I could find out. At one point I had an idea what happened, but I wasn't completely right. My friend said this means I was wrong, but in truth, I was partially correct. But still wrong I guess. ;)
Bottom line, if you liked Big Little Lies, you will probably enjoy this one. It took a while to get to the point, but it was worth the wait.