Phone Bone, Phoney Bone, and Smiley Bone are cousins outcast from their community (for very humorous reasons) to a world completely new to them. The world at large is drawn realistically and inhabited by the good, the bad, and the still deciding.
The cousins spend a great deal of their unintended quest searching. They search for one another, escape from peril, and the truth to evil in the world. The also have one heck of a time along the way.
BONE has something endearing for everyone who reads it. Jeff Smith wrote and drew the story in a manner that any age reader can access it by tapping into familar characters of the past. Phone Bone, Phoney Bone, and Smiley Bone look very much like smurfs. Their cute, largely innocent ways, are reflected in their soft rounded looks. The Rat Creatures are terrificially dangerous looking and create just the right balance between being outright frightening and merely intimdating. Grandma is a hoot and has many Popeye-esque qualities to her. Thorn is a beauty! Need I make the comparison here?
In BONE, it is almost as if Jeff Smith decided to take all of his favorite cartoon characters and set them out on a mythical quest with parallels to Moby Dick, The Lord of the Rings, and the Illiad- minus all the dense reading required of those classic works.
Make no "bones" about it. This is a classic- a children's classic.