Who is Madame Badobedah? Mabel sets out to prove that an eccentric new hotel guest is really a supervillain in this witty storybook about an intergenerational friendship. There's a strange new guest at the Mermaid Hotel -- a very old lady with a growly voice, bags stuffed with jewelry and coins and curiosities, and a beady-eyed pet tortoise. Mabel, whose parents run the hotel, is suspicious. Who is this Madame Badobedah (it rhymes with Oo la la ) who has come to stay indefinitely and never has any visitors? To find out, Mabel puts on her spy costume and observes the new guest. Conclusion? She must be a secret supervillain hiding out from the law. The grown-ups think Madame Badobedah is a bit rude -- and sad -- but when she invites dahlink Mabel for a cup of forbidden tea and a game of pirates, the two begin a series of imaginary adventures together, and Mabel realizes that first impressions can sometimes be very wrong.