Hyperorganized perfectionist Beatrice More is determined to plan a spectacularly professional birthday party for her little sister, Sophie. But she is foiled at every turn: her mother insists on making a homemade cake (disaster!), her father offers up discount mismatched decorations (debacle!), guests are hard to find in their new neighborhood (dire!), and no gift seems remotely special enough (defeated!). Will Beatrice's organizational skills be enough to turn this party around, or will she need a little help from her friends and maybe even from Sophie herself?