THIRD GIRL

Norma, one of three girls sharing a London apartment, seeks help from Mo Hercule Poirot because she believes that she has gone murderously mad. It turns out that she's been kept in an unlikely state of borderline insanity through an incredible assortment of habit-forming drugs and LSD. It seems that one of her roommates (for Pete's sake!) has been masquerading as Norton's stepmother via a wig... Only the grand dame of detective fiction could get such amateur plot published; her devotees have never been demanding on this aspect of good mystery writing.