It began as just another missing person's case. Janice Slattery came to the Merrick Detective Agency seeking help in finding her sister, Joyce St. James, who had disappeared a week ago. Tempted to pass it off as just another young woman who arrived in Hollywood seeking fame and fortune and then dropped out of touch to hide her failure, Janice argues this situation is different. Joyce was a dependable bank clerk who had lived in Southern California all her life. It wasn't like her to vanish, although she had been depressed lately, and she fears Joyce may have come to a bad end. She didn't realize how close to the truth she came. Reluctantly agreeing to give the case three days, Jack discovers that none of his agency cars will start. Suspicious that he has been hexed by gremlins, the little imps that besieged him during the war, he is forced to drive another vehicle to Miss St. James' apartment. There, he finds nothing out of the ordinary except a book of Sherlock Holmes short stories with an odd doodle shoved inside as a bookmark. Taking that, with a gloomy presentment things were not as they should be with him, he determines the doodle may actually be a map. Using an atlas, he traces the meandering lines to a locale in the mountains. Following the directions, he finds himself buried in a billowing shroud of fog and is waylaid at a deserted lakeside cabin that rests on one of the turn-offs on Joyce's map. Determining, more from intuition than fact, Joyce may actually have been there and used the cabin as an escape from her humdrum life, he returns to L.A. to conduct further research on the missing woman. Making inquiries at the bank, Jack discovers the reason for her disappearance: $50,000 is missing and Joyce St. James is the prime suspect. On a trail convoluted by conflicting clues, emotional turmoil as he becomes romantically involved with both Janice and her missing sister Joyce, and haunted by the spectre of gremlins, Jack ultimately becomes a police suspect as a co-conspirator in the bank theft. Embittered and frustrated, he fights against his friends who try to warn him he isn't thinking clearly. Determined to solve the case at any cost, exonerate Joyce and perhaps find a new life for himself, he sets off on a course of disaster. One which terminates with terrible cost.