On an adventure, brothers Wirt and Greg get lost in the Unknown, a strange forest adrift in time. A wise old woodsman and bluebird Beatrice help them find their way. Along the way, Wirt's thoughts envelope him, while the wonder of the surroundings preoccupy Greg. The miniseries -- based on creator Patrick McHale's cartoon short "Tome of the Unknown" -- features animation that evokes a nostalgic storybook feeling, inspired by folk art and classic illustrations. The voices include Elijah Wood and Christopher Lloyd with Samuel Ramey, Chris Isaak and John Cleese among guests.