This is the sequel to Anthony Horowitz's Raven's Gate. It's hard to imagine this author doing a fantasy story with all his Alex Rider creations, but he demonstrates from that series that there's not much he can't do, or won't try to do at least. Book One ended with Matt escaping from the Lesser Malling village, having a new friend and a possibility of meeting another one of the five. Now, what Matt and Richard must do is not only find the other one of the five that Matt has recently had dreams about, but must find an old diary being held by William Morton but then stolen by Diego Salamanda, who wants to use it's secrets to open up another Raven's Gate, the Nexus wanting the opposite. Matt has no trouble with this after he drops himself out of school. He didn't do anything bad. He just had it with the bullying and threw his books in the trash, and then saved everyone's lives with his powers.
The first novel, Raven's Gate, was a decent undercover mystery story with a good series feel to it but death overdose. This one still has a few main character deaths but certainly not as much. There is still a mystery, but it's not the whole point of the story. There is a situation in which Matt and the other one of the five can talk to themselves in their dreams after Matt and Richard head to Peru.
What I liked a lot about this book is not just how nicely it's paced, but because of action during the extra sneaking around being more powerful than the first, you can feel Anthony Horowitz's honour in this Gatekeeper's project. I was too at the start, when it was obvious how Matt was having trouble hiding his uncontrollable ability.