The weakest of all of William Castle's producer/director efforts of the late 1950s and early 1960s, 13 Frightened Girls fails utterly in almost every department. The overlit color photography destroys any support for the mood of suspense in the thriller sections of the movie; and the shifts in tone, from action and terror to light-hearted teen caper, are jarring no matter how many times one sees the movie. Hugh Marlowe and Murray Hamilton play their roles straight, which must have taken considerable effort, especially on Hamilton's part considering that in his first scene he has to fend off the amorous advances of a key female character who is 16 years old. The picture is completely schizophrenic in its structure and content, part spy thriller and part light teen comedy. Disney might have made a movie like this with Hayley Mills -- and there are moments where it makes one think of a kind of distaff answer to the latter studio's version of Emil And The Detectives -- except that it would have been better written and directed, and probably better cast as well. Only Keigh Deigh, as a Chinese diplomat/agent, seems to want to acknowledge the silliness of the film, in a performance laced with touches of wry humor.