3.75/5 - Surprisingly my favourite instalment of the series. Not perfect, but overall enjoyable for a YA mystery. Some of Stevie's actions towards the end of the book really vexed me, but I was more intrigued by the mystery explored here than the Ellingham case covered in the main trilogy. You do not have to read any of the previous books before getting into this one, but it is nice to be familiar with some of the characters before going into the story.