Mmmmmmmm where to start? My daughter is obsessed with mermaids, big time, hence why I was forced to read this. For kids the book is ok, it's all about BFFs and underwater prisons patrolled by hammerhead sharks, ya know the normal kid stuff. For adults it was quite an annoying read, nothing gets explained, like how mermaids can speak underwater and how a human was able to remember a what a particular shipwreck looked like on the bottom of the office. Hey ho this is a kids book after all and she enjoyed it so can't complain. I suspect we'll be continuing with the series at some point.