Now an adult with three children, bank teller Michael Banks learns that his house will be repossessed in five days unless he can pay back a loan. His only hope is to find a missing certificate that shows proof of valuable shares that his father left him years earlier. Just as all seems lost, Michael and his sister receive the surprise of a lifetime when Mary Poppins -- the beloved nanny from their childhood -- arrives to save the day and take the Banks family on a magical, fun-filled adventure.