After losing her advertising job in San Francisco and canceling her wedding (though not her engagement) to an overprotective artist, Melissa heads off to a new job as au pair to the family of a member of Parliament. She harbors grand illusions about life in England, but the vaguely aristocratic Haig-Ereildoun household falls far short of Melissa's imaginings. Philippa Haig-Ereildoun refers to Melissa as "her American girl" with a mixture of pride and contempt, expects her to bathe in cold water already used by the children, and, most importantly, entreats Melissa to "try to speak as we do." Heaven forbid the children should pick up an American accent!

But then there is Nanny, the gloriously eccentric octogenarian who raised Mrs. Haig-Ereildoun, who offers comfort and much comic relief; nine-year-old Trevor, Melissa's charge, whose wisdom and companionship relieve many a lonely day; and Simon, a young scientist who couldn't be more different from her fiancé.

In the spare moments between her labors, Melissa confides the family idiosyncrasies and her own romantic musings to her diary; the result is an unforgettably entertaining and delightfully sharp-sighted comedy of manners.