A chase in which the hound becomes the hare when his search threatens to disclose too much for comfort. Private agent, Mercer, shabby and on the verge of selling his pride and loyalty, is ready to inform his client that the man, Uccello, whom he is to find, is dead, but the treatment he receives, at the hands of the police, Count Boria and his henchman, the murder and assassination of which he is accused, and the attacks he undergoes, stiffen up his spine and make him turn against his pursuers. In his patient gathering of detail, he unearths the past of Uccello which proves him to have been a thief, genius, partisan and traitor, and discovers the Uccello of the present a hard-to-catch quarry. But in spite of everything, Mercer gets his man and keeps his integrity. Played out in present day Italy, this has a validity of character that offsets its melodrama.