Phil And The Mysterious Whirly Walls — Jennifer Lee

Phil and three other nine year olds wake up to discover that they are the last four humans on earth. The only clue to the disapperance of the entire human and animal species are the mysterious whirly walls that are popping out of nowhere. Together, they embark on a brave and comical adventure to find out how to get everyone and every animal back. Spoiler alert: May involve aliens or monsters of some sort.