Somewhere in the middle of the immense and thick Covington Forest exists a small village of old-fashioned people leading a simple life. Led by a group of elders including Edward Walker (WILLIAM HURT), August Nicholson (BRENDAN GLEESON), Alice Hunt (SIGOURNEY WEAVER) and others, the villagers work hard in their self-sustaining hamlet. No one ever leaves or visits due to reports of monsters in the woods that won't enter the village's perimeter as long as its inhabitants don't enter theirs.
Yet, Alice's adult son, Lucius (JOAQUIN PHOENIX), wants to do just that, but only to obtain medicine from a nearby town that might help save some of the inhabitants in the future. Everyone is against the idea, particularly when some livestock end up being killed and skinned, seemingly as a warning to stay out of the woods.
Not everyone is disappointed that he doesn't get to go, however, especially Edward's blind adult daughter Ivy (BRYCE DALLAS HOWARD). Since Lucius turned down her sister's romantic intentions, Ivy -- who's something of a tomboy and good friends with Noah Percy (ADRIEN BRODY), the village's mentally challenged resident -- is now determined to make the reserved Lucius hers.
With increasing incursions from the creatures in the woods, however, they have something more important to focus on than love. And when a person is severely injured and needs medicine that can only be found in an outside town, one of the villagers must make their way through the woods and contend with a potentially dangerous or deadly encounter with one of the beings.