"Pirates Past Noon," the fourth book in Mary Pope Osborne's Magic Tree House series, follows siblings Jack and Annie as they are whisked away by the magical tree house to a deserted island during the golden age of piracy. There, they are captured by the greedy Captain Bones and his pirate crew, who believe the children know the location of Captain Kidd's lost treasure. With the help of a mysterious parrot named Polly, Jack and Annie must use their wits to escape. Upon returning home, they finally discover the identity of their magical benefactor: Morgan le Fay, the enchanting librarian of Camelot.