Series
There are 5 books in the Fablehaven series.
Published between 2006 and 2010, in the same order they are meant to be read.
Fablehaven is Brandon Mull's middle-grade fantasy series, beginning with Fablehaven. Siblings Kendra and Seth Sorenson discover that their grandparents' estate is a hidden refuge for magical creatures, and that keeping it hidden is dangerous work. The story continues in the sequel series Dragonwatch.
All 5 books total 2,372 pages.
The Books Oracle — track the series you are partway through, and see what to read next.