Chemist John Emmett quickly learns that his pick-up, Ann Nicholson, with whom he is hitching a ride west, presents an irritating mystery -- for she is either the victim of unrelenting persecution or a treacherous maniac -- and definitely not the companion for a safe drive. Later the question is whether she is a heroine of the French resistance or traitor to it, and the answers to it and all the rest are kept confused by double- trouble caused by deliberate doublecrossing. Wanted by a county sheriff, pursued by a doctor and his hard to handle blonde nurse, tagged by the FBI, Emmett and Ann reach her journey's end where definite identification await her. Even here there is another twist but by now Emmett takes it in his stride. Psycho-thriller, well-paced and produced. SEP serialization.