Doll museum burglarized!

Kayo Benton and Rosie Saunders race to the museum to check on their favorite dolls. Everything seems okay. But the keys to the display cases are missing. And the musical mohair cat is playing a song...as if squeezed by unseen hands. Someone...something...is watching them. But who? And who is the strange-looking soldier in the rumpled uniform who's following them, beckoning them to return? Rosie thinks it's a ghost -- a ghost with a tragic secret. Soon they're back again, locked in the museum after closing time, trapped between two ghosts -- and a pair of ruthless thieves...