In Silverstein's The Missing Piece (1976), a circle with a dot for an eye set out to find the wedge-shaped piece whose absence, in the pictures, made a mouth-like gap in the circle. Here, in a similar spirit, the piece itself sits passively, "waiting for someone to come along and take it somewhere." Otherwise this is the same story, with the same message: where the earlier circle finally found a piece but rejected it because its presence prevented the circle from singing, this piece--after many unfit candidates and one trial match which it outgrows--finally meets the independent Big O. The O, complete in itself, isn't missing a piece, but does inspire this piece to roll along independently too. Soon the effort rounds off the wedge and it catches up with the big O to roll with it side by side. Like its companion piece, this has a more contemporary message than Silverstein's The Giving Tree; but even interpreted broadly it doesn't speak specifically to children's needs, and the innuendos make it more appropriate for coy adults.