Marsha Hunt seems far too mature and intelligent for the pulpish goings-on in Mary Ryan, Detective. Still, Hunt was a pro (for that matter, she still is), and she managed to survive this Columbia "B" without egg on her face. Assigned to get the goods on a notorious fence, detective Mary Ryan (Hunt) poses as a prison inmate to gain the confidence of one of her quarry's confederates. Upon being sprung from jail, Mary goes to work for the fence--and, predictably, nearly gets bumped off when her ruse is revealed. Featured in the cast are such crime-meller habitues as John Dehner, Ben Welden, Paul Bryar and Ralph Dunn.