Another good book by Agatha Christie. Luke Fitzwilliam meets an old lady on a train to London. He finds out that she is going to visit Scotland Yard to report a series of crimes. According to this old lady, three murders have already occurred and she is sure another is about to happen. She names all the alleged victims and the person she fears will be next. Luke pooh-poohs the idea until he find out the next day that this elderly woman had been killed in a hit and run. Then a few days later, he reads an obituary for the person this lady feared would be the next victim. Luke, a former policemen, decides to investigate.