Bought this book for my son who is 9 years old and in the 4th grade because I thought it would interest him that Ben, the protagonist, is a 12 year old boy who stumbles into spy school. I will say right off, that there are a few occurrences of words such as "ass" or "damn" in the novel in case that matters to you. I rarely notice language when I'm reading for myself, but as I try to provide my son with literature that is closer to his reading level, I definitely notice these things more. Spy School
is full of action and comedy. There were several parts that made me chuckle out loud. The "romance" in this series involves Ben's crush on a girl super spy a couple years older than himself. A handful of times he references her signature scent of being a combination of "lilacs and gunpowder". The interactions are always cute between the two.
Despite the age recommendation for this book being 9-12, I have no problem stating I would be interested in continuing this series on my own if my son hadn't loved it as well. Looking forward to the second one in the series, Spy Camp