Those who walk away - Patricia Highsmith

The honeymoon is over, as they say, the bride dead by her own hand. Ray Garrett, the grieving husband, convinces the police in Rome of his innocence, but not his thuggish father-in-law, an American painter named Ed Coleman, who shoots him at point-blank range and leaves him for dead. Ray survives, however, and follows Coleman to Venice, where the two fall into an eerie game of cat-and-mouseColeman obsessed with vengeance and Ray equally insistent on clearing his conscience, though each is at once the hunter and the hunted in a duel composed of tension, hiding, and guessing, and at times punctuated by violence that, even as each manages to walk away, draws them nearer to death.