I remember concluding my review of "I Am Number Four" by saying I enjoyed the book, but I would not be buying the sequel. But sometimes the passage of time makes you realise that there was more that you liked about a book than the things you didn't, and overall my experience of the book was a good one. So when I found myself with the chance of receiving a free advance copy my immediate reaction was to jump at it, because I genuinely wanted this second book to be better so I could enjoy without any disappointments finding out what happens to the characters.
Thankfully, The Power of Six is a big step up in terms of plotting and pacing, and although you know there has to be a big battle of some sorts at the end, there's no "read this all before" feeling, and there are some interesting turns along the way, whereas in the first book if you took a guess at where a plot point was going, you were usually right. The best thing about this second venture into what is now being called the Lorien Legacies series is that it focuses much more on character, and for the most part it gets it right. I felt with the first book that I only really got to know part of John's character, largely because when it focused on his relationship with his CÍpan / adoptive father Henri, the characterisation was well realised, but when away from Henri it followed the well trodden path and, though fairly enjoyable, was predictable and didn't always ring true. Second time around, the writers have fixed this and for the first time really allow the reader to really get to know the characters of John, Sam and Number Six and how they relate to each other. Plus, which also works in the books favour, it brings in a new character - Marina, who is a Garde living in a convent in Spain, where her CÍpan has abandoned her role as protector and joined the order, leaving her charge not only worried about the dangers that she perceives may be catching up with her, but also desperate for news on the locations of the others like her.
The two stories are well balanced, and you never feel that you want the chapter to end so you can get back to reading the other. Without spoiling anything for you, at certain points the two stories intersect, and by the end of the book you know that this series is gearing up for a third book where all the surviving Garde come together and start to plan their fight back. If you were a fan, or perhaps not a fan, of the superpowers and monsters elements of this series, know that both feature heavily in this book. I haven't seen the film of the first book, but can make a guess that a film of this one would need double the special effects budget.
It's worth noting that the Mogadorians continue to be the mysterious and unrelenting threat that they were in the first book, and if you want deeper information as to what they are and their wider motivations, you're not going to get it here. But before you jump to conclusions, let me tell you that in the context of this particular book, and of the ongoing series itself, this is actually a calculated risk that pays off. The continuing mystery behind the Mogadorians and the lack of any central villain works in the favour of this book, and when you reach the end, there are strong hints that a major bad guy will come to the fore in book three, and with him a greater understanding to the reader of what this whole conflict is about. The writers achieve that difficult balance between bringing the book to a satisfying conclusion and making you look forward to what you'll discover next time round.