Design in Evil (Popular Library 124)

Miriam Lake found herself in an alarming situation the night she came aboard the luxury yacht "Donna Louise" for an interview with a "Mrs. Murchison" who was seeking a governess for a backwards child. First, Mrs. Murchison turned out to be a man -- Donald Murchison. Then, Miriam learned that everyone on board believed her to be Murchison's long-lost niece and a victim of schizophrenia, causing her to adopt a strange new personality.