Inspector Bob Deering is on the trail of ‘Sparkle’, an international jewel thief. He meets a newspaper reporter, Pat ( Jessie Mathews ), who is writing a story about a film star and obtaining information by pretending to be her maid. When she accepts an invitation from Bob for an evening out, she is sacked and, to save her reputation, she steals a necklace. Unfortunately, the necklace actually belongs to a friend of Bob and leads him to suspect that Pam is actually the elusive ‘Sparkle’. His personal and professional beliefs collide, but which will he listen to?