There is not a ton of judo stuff in this book, and you can bet if there was, I'd be the first person complaining about it. On the judo, I think the author got it just right on the amount of judo background.
On the substance, there is way too much fighting people with guns and knives, yet coming out on top through the use of judo throws. This is not exactly sending the right message to kids.
There is a decent story here which is mostly linear, with basically everybody up to no good except for the teacher, and your fellow martial artist.
There is one ridiculous ending where everything is revealed in a few paragraphs of exposition by your dojo master. The pictures are pretty good, though. I especially liked the one where I jumped off a moving boat to rescue someone without telling anyone, and when I end up in the water, not only can I not find the person I was trying to rescue, the boat keeps going, and I have a very forlorn stranded look. What would you title this picture of kid stranded in the ocean? It hearkens back to the very scary movie Open Water.
The most ridiculous part of this book is the dialogue provided by the Jamaicans. Some real samples:
"I canna do it, mon! Me brakes are no good!" (Don't you mean me brakes IS no good?)
"The nearest one be in Kingston town." (I believe the grammar requires a mon.)
I also comment on the unusual hairstyle of the Jamaicans, which turns out to be dreadlocks. I haven't seen dreadlocks before? Am I so into judo that I don't watch tv?
The final ridiculous thing that bears commenting on is where I use judo to deflect a knife attack, and after the rest of the attackers gang runs away, I help one attacker up, and have a friendly chat with him. I mean, you don't want much violence in these books, but this kind of stuff does detract from the suspension of disbelief. Everyone knows, there are plenty of bad things that happen to you in a CYOA book.
In the final analysis, this is a middle of the pack book. I am curious to read the rest of Brightfeld's martial art "Master" series to see how they hold up.