The young and pretty Judy is the Cinderella in the household of her bullying aunt Lady Blundell and her ill-tempered cousin Isabel. Sir John Shale, who is engaged to Isabel, asks Judy to translate for him a business letter in French from oil millionairess Myra Hoffman. Judy lays a plan, when she learns from the letter that Myra will be calling at Sir John's flat that same evening. TV adaptation of Ellis' 1936 farce.