Read the full review at: http://polkadotbookblog.blogspot.co.uk/2014/07/agent-21.html
For starters, I was really excited for the genre of the book because I was a really big fan of the Alex Rider series by Anthony Horowitz, so the books genre really appealed to me because it sounded so similar in a lot of ways. Which is why in the In the beginning I was really gripped and excited for what was to come. The prologue was so amazing! Yet I felt that the book dragged a little after that, so it took me a while to get into it and to really enjoy the writing. Having said this, I did find the story highly enjoyable and I loved how it ended like everything tied up and connected in a neat little bow. Another thing that really made this book for me was the realistic detail that it had when it came to the mission and the training. I really felt that I was learning along with Zak and it was really believable spy/espionage skills, like the Morse code and navigation lessons that were integrated into Zak's training. I just absolutely loved those parts of it!
The characters in the book were strong and relate-able, so they felt more realistic and believable to me. Which helped me to like them and cheer them on from the sidelines because you just wanted them to survive. But then I felt that in some cases they were a little underdeveloped to me. However I think that was more down to the fact that it was the first book so I just wasn't used to the writing yet.
Overall, Agent 21 is a really enjoyable read that does encourage you to buy the rest of the series because you do get carried away with the characters and the missions that they go on. There was action, adventure, mystery as well as lovable characters that have a lot of room for growth. So while I didn't love it, I am really excited to carry on with the series and find out what the rest of the adventure is like for Zak Darke.