After finding a mysterious, handmade field guide in the attic of the ramshackle old mansion they've just moved into, Jared; his twin brother, Simon; and their older sister Mallory, discover that there's a magical and maybe dangerous world existing parallel to our own, the world of faerie. The children want to share what they know, but the faeries will do everything possible to stop their secrets being revealed.

Eleven-year-old Nicholas Vargas only thinks his life has been turned upside down after his developer father remarries and moves his new wife and daughter into the soon-to-be completed Mangrove Hollow. But an "expedition" to a nearby lake turns up a little nixie with a giant problem--the huge, lumbering, fire-breathing variety--and it's up to Nick, his stepsister Laurie, and his big brother, Julian (plus a familiar face from the original Spiderwick...

Kenny Rabbit's jealousy leads to trouble after Dante the Manticore escapes from an evil witch's magical book and reunites with his old friend, Grahame the Dragon.