Author: Landy, Derek
Interest age: from c 9 years 
Published 29/03/2012 by HarperCollins Publishers (HarperCollins) in the United Kingdom as part of the Skulduggery Pleasant series 
Paperback | 608 pages
Meet Skulduggery Pleasant: detective, sorcerer, warrior.
 Oh yes. And dead.
 The Necromancers no longer need Valkyrie to be their Death Bringer, and that's a Good Thing.
 There's just one catch. There's a reason the Necromancers don't need her any more - because they've found their Death Bringer already, the person who will dissolve the doors between life and death.
 And that's a very, very Bad Thing...