The Blob begins as a sole individual, playing a game of tag. As soon as s/he catches someone, s/he joins hands with him or her. Now the new person part of the Blob, too, and they both set out, hand in hand, in search of victims. Everyone the Blob catches (only the outside hand on either end of the Blob can snatch at players) joins hands with it and becomes part of the lengthening protoplasmic chain. And the Blob keeps growing. The thrilling climax occurs when there's only one player left to put up a heroic last-ditch stand.