Detective Barker has his work cut out for him when his red-haired nanny, Kate Blond, turns out to be a master thief in disguise. Barker’s close friends are a wealthy count and countess who has recently purchased a valuable piece of jewellery at an auction. With a poisoned sewing needle, Kate knocks the countess out and steals the jewellery. She sets the countess’ clock back an hour so the nanny-job is a bulletproof alibi when Barker investigates the case. Barker is at a loss until his trained eyes spot a red hair at the crime scene.