Calypso loves the new-old house she lives in with her two mamas. She doesn't even mind that a ghost lives there too -- until he ruins their holiday cookie party! Is there something he doesn't like about parties? Or holidays? Or cookies? With help from the two mamas and her new friend Abbey, Calypso searches for clues in all kinds of places, like the library, the local cemetery, and even her friend’s house. But time is running out, and Calypso is determined to solve the mystery -- before the ghost can ruin their next party.