Tom Ward's mom went to her homeland to help fight the dark forces. Her homeland is Greece and if you recall Greek mythology you will realize there are a lot of supernatural bad creatures in there.
Much to Tom's surprise she came back asking him for help which would be essential in her plan to stop a coming Big Evil. The said evil is so big that she and Tom would be forced to ask local dark forces for help. This was completely unacceptable to Tom's master the Spook. Now Tom had to choose between the loyalty to his mom and his master - the two people he holds in the highest regard.
I already revealed the main theme of this book: can one use lesser evil to fight greater one? For the Spook it is absolutely out of the question. Tom however would end up in a lot of situations where such compromise was practically unavoidable if he was to save people dear to him. What are the consequences of these compromises?
It probably would not be a great spoiler if I mention that the biggest part of the book takes places in Greece. This makes for a change of scenery and it does not always work as quite a few of my friends gave this book a lower rating than usual. For me however the different shades of gray and practically complete absence of black-and-white contrast more than made up for the new scenery.
I should mention that quite a few good people die in the series. This book probably hold a record for a number of such deaths.
The final rating is 4 stars. I am not sure how good the following books are, but for now if you are looking for young adult horror reads - look no further than this series.