There is not a for sure release date, but judging from the pattern of the release dates of books 3 and 4, it will come out on February 27, 2010. KEEP IN MIND THAT IT IS JUST AN ESTIMATE. If you want a less rough estimate, it will come out in either late February or early March of 2010.
it is now out it came out in February
Yes, Book 5, Keys to the Demon Prison set to come out March, 2010
there is no book 6. :(
It's out. ;D
There are 5 Fablehaven books by Brandon Mull.
5
It came out March 2009.
2010
March 23, 2010.
March 23rd 2010.
spring of 2010
The book Fablehaven: Keys to the Demon Prison was released on March 23, 2010.