Upon moving into the run-down Spiderwick Estate with their mother, twin brothers Jared and Simon Grace, along with their sister Mallory, find themselves pulled into an alternate world full of faeries and other creatures.

Mallory Grace: What happens when Mulgarath gets the book?
Thimbletack: I die. You die. We all die. Bye-bye.
Mallory Grace: [turns to Jared; voice quavering slightly] What does he mean, 'we all die'?
Jared Grace: I think he means... we all die.
Tow Truck Driver: [after running over an invisible monster] Did I hit someone?
Jared Grace: Yes! Thank you!
Hogsqueal: Vengeance or death!... Hopefully vengeance.
Jared Grace: [seeing Thimbletack as a Boggert] And they say *I've* got anger issues.
Helen Grace: [when preparing to defend the house] "Good we were New Yorkers."
Aunt Lucinda Spiderwick: [showing scars on forearm] If they say 'suicide' and you say 'goblins', this place is where they put you.
Jared Grace: Why can't I see you?
Thimbletack: You don't see us, now you do, but only if we want you to.
Jared Grace: [reading Arthur Spiderwick's book] What the hell.
[repeated line]
Hogsqueal: Bird!
Mallory Grace: Thanks, Spock, you're the pride of the Federation.
Jared Grace: Why can't I see you?
Thimbletack: You don't see us, now you do, but only if we want you to.
Simon Grace: [refusing to help Mallory attack Jared] I'm a pacifist.
[last lines]
Hogsqueal: [as the griffin is soaring far overhead] Fly as you want. Griffin! I swallowed an ogre whole. You could be next!
Jared Grace: [after Mallory hits the wall and a piece of it fall to the floor] Great, I'll get blamed for that!
Hogsqueal: Do birds live in these little houses?
Jared Grace: Yeah.
Hogsqueal: Oh my gosh, that's genius! Who thought of that? You can stick your tongue right in it!
[begins slobbering over a birdhouse]