Knowing Where to Look

One evening, a woman received an unexpected call from a ticket clerk at a major airline. He read a list of names and asked if she knew any of the people. "Yes," she said, "they're all friends of my son. How can I help you?" "The crew was cleaning a plane, and they found this address book," the clerk explained. "After seeing no identification, we looked through the entries and found one we knew could help us. It was under M for Mom."