Mary Anne just loves her little kitten, Tigger. So, when he disappears one afternoon, Mary Anne is a little concerned. The next morning Tigger is still missing . . . and Mary Anne is frantic. It's time for an emergency meeting of the Baby-sitter's Club. The girls pool together a reward for the return of Tigger, and they search everywhere for him. But there's still no sign of him . . . until Mary Anne receives a frightening letter in the mail. Someone has taken Tigger, and Mary Anne must pay a hundred dollars to get him back. Is this some mean practical joke . . . or has Tigger really been cat-napped?