内容简介
Thebabysitterisasurprise,saysDad,buttoArthurandD.W.,she'smorethanasurprise-she'samystery!Theirimaginationsrunwildwonderingwhowilltakecareofthemfortheevening-willitbeapirate,arobot,aliensfromouterspace-orevenworse,Mr.Ratburn?Whenthedoorbellfinallyrings,theirpanicturnstoreliefwhentheyfindoutthattheirbabysitterisn'tsuchamystery,afterall-it'sgoodoldGrandmaThora!