Lily is 9. Her sister, Daisy, is 1. But she's no ordinary baby. Somehow, when she was born, something went wrong. And now Daisy is a Witch Baby. Nobody knows this but Lily. She's the only one sho can see when Daisy makes the fridge float in the air, or turns people into slugs, or summons up her very stinky dog, Waywoof.

They have just moved to a new neighbourhood and Mum decides to throw a party. She sends Lily and Daisy out to deliver the invitations. They meet some odd characters along the way. Will the party be a big success, or will Daisy's magic mean things make it even more chaotic than normal?