Abby Cadabby is feeling blue because it's her birthday—and no one remembered! Even a walk around Sesame Street with Elmo doesn't cheer Abby up. But there's something going on behind the scenes, and toddlers will figure out just before Abby does that there's a happy—and pink—surprise waiting for her right inside her own front door: Grover, Murray, Zoe, Big Bird, and Cookie Monster are giving Abby a birthday party after all!