Brave, clever and never more than a whisker away from adventure When the museum's visitors are gone for the day, it's time for the cats to come out to play.

The kittens can't wait to welcome a group of school children to the museum's first ever sleepover Especially Bianca, who loves people fussing over her. So when Bianca goes missing after a squabble with the other kittens, they worry that she has run away with the children.

But the rats have been sniffing around the sleepover too. Could the kittens' old enemies be behind Bianca's disappearance?