First and foremost, congratulations on finishing your first novel! It takes a lot of work and dedication. Great job for taking on that beast.
Read the story now
Okay, on to business. Synopses are hard. As a writer, it’s challenging to know what to put in a blurb and what not to. Because we love all of our stories as if it’s our babies. I have a hard time with this myself. Maybe you could have a beta-reader read your story and blurb and mark off what they believe shouldn’t be there.
The plot itself was strong initially (first couple of chapters) but was watered down once it jumped to being a story about Karie and John instead of Annie. It would be better to separate the two plot lines and make a thriller series rather than a single novel.
There were some pacing issues, shifts in tense usage, and grammatical issues, but all of these problems could be fixed with a rewrite. Also, be careful of your usage of exclamation marks.
I found how John and Karie fell in love was unrealistic, but you can fix that if you give them a more substantial back story. Example: Have them keep in touch with letters. So they feel they still know each other somewhat. We writers love creative license, but be careful not to overuse it.
Love does conquer a lot, but… It doesn’t make you capable of inhuman feats unless the writer writes in a plausible reason(s) why it could happen. So you might want to give John more time in the dojo, like some years. Then it would be possible. You could even use that time for the main characters’ love to truly bloom.
Even with that said, I think the author has potential, and I wish him the best in his future writing endeavors!