"When catastrophe strikes their beloved upstairs neighbors, the Vanderbeeker children set out to build the best, most magical healing garden in Harlem--in spite of a locked fence, thistles and trash, and the conflicting plans of a wealthy real estate developer"-- Provided by publisher.

Katie is dreading the boring summer ahead while her best friends are all away at camp -- something that's way out of Katie and her mom's budget. But when Katie gets a job catsitting for her mysterious upstairs neighbor, life gets interesting. First, Madeline has 217 cats and they're not exactly normal cats. Also, why is Madeline always out exactly when the city's most notorious villain commits crimes? Is it possible that Katie's upstairs neighbor...