We are sorry we didn't post this before.
Rick Riordan said in his twitter that he wrote another book called The Staff of Serapis, it's a sixty-page crossover story of The Kane Chronicles and Percy Jackson. It´s a story the fans have asked for.
In the book Annabeth Chase meets Sadie Kane!!!!!!!!!!!!!!!!!!!!!!
In this adventure Annabeth encounters more oddities in the subway than usual including a two-headed monster and a younger blond girl who reminds her a little of herself.
The Staff of Serapis was released on Tuesday, April 8, in the back of the newly released US paperback edition of The Mark of Athena!
The story will be available in e-formats, with the cover below, on May 20. The e-format will also include the first sneak peek of The Blood of Olympus, and if you buy the version with the audio bundled in, you will get to hear Rick Riorda nnarrating.
You can't wait to read it now? Then you are in luck because Rick Riordan (or Uncle Rick it depends if you are one of his fans or not) released the first chapter of the book in his webpage.
Here is the link http://rickriordan.com/Files/Documents/StaffofSerapis_excerpt_trade_pbk.pdf
This is the cover:
More information in Rick Riordan's blog:http://rickriordan.blogspot.com.es/2014/04/the-staff-of-serapis.html
We also let you the official twitter of Rick Riordan:https://twitter.com/camphalfblood