Abby and Jonah take a trip through the magic mirror and finally end up in Jack and the beanstalk (which happens to be Jonah's favorite story ever)--but things soon start to go wrong, and the children have to try and set the tale right, even if it means trading their dog, Prince, for the magic beans, climbing the beanstalk (three times!), and reaching an amicable settlement with the giants (Magnus and Philippa, who are really quite nice), and the sneaky trader, Devin, to get their dog back.