This was a much better Skulduggery Pleasant novel, yet it had its own set of inconsistencies and issues such as plenty of info-dumping/name-dropping. There were perhaps too many characters for this story and, on occasion, Derek Landy lost control of a couple of them.
The big problem for me is how Derek Landy races through everything so fast that he sometimes fails to slow down and allow for a more nuanced or subtle approach to building his world and characters. In that sense there is a loss of complexity to the story. That all considered I do believe this is something children would not notice, in fact I think this is the kind of story that they would love. However I personally also believe that [b:Revenge of the Witch|298567|Revenge of the Witch (The Last Apprentice / Wardstone Chronicles, #1)|Joseph Delaney|http://d202m5krfqbpi5.cloudfront.net/books/1362370505s/298567.jpg|3496896] would be a better series for adults in a similar vein to this novel.
So, the plot, well it follows another attempt to resurrect the Faceless Ones from their realm beyond Earth and obviously it involves some foiling of said attempt. Whether the foiling succeeds fully or not is up to you to find out. I could be taunting you with nothing or something. But I will say if you appreciated the other books you should find this to be right up your alley. The descriptions of the Faceless Ones would make for a really great film or television series and I think would creep a lot of kids out. So maybe they'd enjoy these for the thriller and action aspects.