These children are spoilt as anything. Driving home from Aunt Jane's, they spot a lighthouse for sale, and immediately beg grandfather to buy it for them so that they can spend a few weeks(!) of their summer there. Grandfather, who is a poor example of decent behaviour at the best of times, does not tell this grabby foursome to shut their traps and stop being such gimme pigs, but he should. Hence the mystery in the lighthouse, because when you've been trained to be just this entitled - and what a contrast to how attractive these kids were in the first volume of this series, when they made the best of very little without complaint - it's only a matter of time before you start poking your noses into other people's business.

On the plus side, there actually is a nice kid in this. Larry, the subject of said mystery, is a marine biology nerd of the highest order. He spends his time running experiments on seaweed and plankton - having done this myself I am predisposed to like him - and being disinterestedly focused on the welfare of others... instead of merely interfering out of boredom.