This blog will be updated when new information becomes available.
Excerpt of SoS 2.0

It's another crossover between TKC and PJO/HoO. It's Sadie and Annabeth. Woo. Yay. It will come out with The Mark of Athena paperback release on April 8th.

And to explain the whole do I have to buy the book thing in the wise words of Rick Riordan...

"Well, the story will be released first in the paperback edition, since I wrote it specifically to promote the paperback's release, but fear not. Eventually there will be another way to get "The Staff of Serapis." Just as they did with "The Son of Sobek," Disney will be releasing "The Staff of Serapis" later on as an e-single and audio, read by yours truly. As soon as I have more information about the exact e-release date, I will let you know. As always, this information only applies to the US market, as that's the only country I get info for. I can't say if/when it will be available in other countries and other translations."

If you want to know the summary or more information about the book you can click on the source below or you can go to the wiki page. You know... Because it's a wiki...

Source: Rick Riordan's Blog

P.S.: It has the same abbreviation as The Son of Sobek, so I've just been calling it The Staff of Serapis SoS 2.0 to distinguish it. Let's hope that catches on.